Observability, security, and operational readiness

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A running service needs evidence that its customers' obligations are being fulfilled, plus controls for acting safely when they are not. An SLI (service-level indicator) measures an outcome over an explicit eligible population; an SLO (service-level objective) states the target for that indicator. An error budget is the allowed service shortfall, while burn rate measures how quickly that allowance is being used. Financial safety failures are tracked separately and cannot be excused by spare availability budget. Start with that distinction, then connect each outcome to diagnosis, access, release, and recovery.

Evidence notation: C identifies a claim in the claim register, A a dated AWS source, F a foundational source, and CS a finding in the repository case study. The source index supplies the full source details. These labels are lookup aids, not facts to memorize.

This chapter operates the authority and recovery contracts already reviewed in reliability and correctness, the three fintech architectures, and the cost/capacity model. It does not promote telemetry into authority. An accepted order, execution, reservation, obligation, settlement, or posting is true only at its named authority; projections and transport dashboards are diagnostic evidence.

Inference: all targets, windows, thresholds, exclusions, page policies, and retention periods below are unvalidated planning scenarios. They require product, risk, compliance, security, and on-call approval plus measurement before becoming production commitments. AWS service documentation supplies component semantics, not these business objectives.

Six business SLO contracts

Read each contract in this order: outcome, authority boundary, eligible population, good and bad outcomes, then target and response. Keep incomplete obligations in the denominator. SLO01 covers a durable order result; SLO05 covers clean financial reconciliation. Their targets require different alerting logic because a target with no allowed error cannot use a normalized error-budget division.

The good/eligible definition comes first. A rejected invalid command is not a failed accepted command; an unresolved unknown cannot be discarded from the denominator. Planned maintenance is excludable only when the named product owner approved it before the window, clients received the contracted behavior, and the SRE owner separately monitors exclusion count and duration. Emergency maintenance, provider ambiguity, correctness breaks, and reconciliation unknowns are never quietly excluded.

Model details · task11 slos

SLO|SLO01|A customer receives one durable acceptance or deterministic rejection for one logical order|Order command record and authoritative order lookup observed at API edge; transport progress is not acceptance|Every eligible command has one matching durable accepted or deterministic valid product/policy rejection within 2 s and one fingerprint maps to one order|Snapshot at authenticated syntactically valid non-test admission before the product/policy decision; accepted and deterministic valid rejections remain eligible for the whole window|Budgeted service bad: no durable deterministic outcome by 2 s, including an owned break until completion. Latency population: every eligible admission; incomplete outcomes are deadline-censored and latency-bad, never absent. Safety counters: lost accepted command, mismatched fingerprint, duplicate logical order|service_good divided by admission_snapshot_eligible; latency_bad divided by the same eligible population, with actual completion latency or at least window-end censoring for incomplete outcomes; safety counters reported separately|Per product region client class and tenant fairness cohort|rolling 28 days plus 5 min symptom window|Inference: 99.90 percent and p99 at most 2 s; unvalidated planning scenario|Only pre-approved test traffic or scheduled unavailable product window; Product owner approves and SRE owner monitors exclusion ratio|0.10 percent applies only to budgeted service/latency bad; safety counters have threshold zero and never consume availability budget|Command store transitions joined to API receipts and accepted-order manifest|Order API owner|BRN01 BRN02 for budgeted service/latency; immediate safety interrupt outside budget|One fingerprint one order one durable result; accepted manifest has no gap|A load test or production baseline cannot meet target without denominator manipulation|Inference: C117; F14 F15 F16 retrieved 2026-08-22; F39 retrieved 2026-08-23|FSR01 FSR02 FSR03 FSR08 FSR11 FSR12
SLO|SLO02|An accepted order's execution facts reach each required durable consumer without changing execution authority|Execution or matcher authority to consumer inbox or governed open break; portfolio and notice are not execution authority|Required consumer durably records source execution identity and version within 5 s; opening or owning a break is not good and remains bad until the consumer outcome completes|Snapshot when execution authority appends an execution whose versioned contract requires that consumer; later route, expiry, break, or configuration changes cannot remove it from the window|Budgeted service bad: required durable consumer record absent after 5 s, including owned breaks until completion. Latency population: every snapshotted obligation with incomplete outcomes deadline-censored and latency-bad. Safety counters: lost required fact, unexplained duplicate effect, unresolved stale/skipped version|service_good divided by obligation_snapshot_eligible; latency_bad divided by the same eligible obligations using actual or censored latency; each safety counter is separate|Per consumer architecture partition and priority lane|rolling 28 days plus 5 min symptom window|Inference: 99.90 percent and p99 at most 5 s; unvalidated planning scenario|Governed consumer not-required flag approved by Domain owner before event; Messaging owner monitors excluded volume|0.10 percent applies only to service/latency bad; lost fact duplicate effect and unresolved version safety counters have threshold zero|Execution journal or durable authority joined to outbox receipt and consumer inbox|Execution and messaging owners|BRN01 BRN02 for budgeted service/latency; immediate safety interrupt outside budget|Authority and inbox manifests balance by execution ID and source version|Replay or fan-out produces an effect twice or hides a required consumer|Inference: C117 C118; F14 F15 F16 retrieved 2026-08-22; F39 F40 retrieved 2026-08-23|FSR02 FSR03 FSR04 FSR05 FSR06 FSR11 FSR12
SLO|SLO03|A customer portfolio view states an as-of time and converges to recovered order execution and ledger authorities|Versioned projection watermark compared with authority manifests; projection never authorizes cash securities or corrections|Every eligible account observation includes required source versions through an authority watermark no older than 60 s|Snapshot each supported account observation obligation when an authoritative change is admitted; rebuild, account inactivity, or an owned gap cannot remove it from the window|Budgeted service bad: freshness older than 60 s or incomplete observation, including owned gaps until repaired. Latency population: every snapshotted observation with incomplete results censored and latency-bad. Safety counters: wrong exact amount, missing as-of, or derived state authorizes finance|fresh_service_good divided by observation_snapshot_eligible; freshness_latency_bad divided by the same eligible observations using actual or censored age; safety counters separate|Per tenant account build ID and source partition|rolling 28 days plus 5 min symptom window|Inference: 99.50 percent and p99 freshness at most 60 s; unvalidated planning scenario|Approved unavailable read product window only; Product owner approves and Projection owner monitors excluded accounts|0.50 percent applies only to budgeted freshness; wrong totals missing as-of and unauthorized projection use have threshold zero|Projection manifest and watermark joined to orders executions postings and balances in exact units|Projection owner with Domain owner for authority discrepancy|BRN01 BRN02 for budgeted freshness; immediate safety interrupt outside budget|No gaps; exact control totals and watermark match; vNext manifest approved before cutover|A backfill matches counts but not quantities exact values or source versions|Inference: C117 C119; F14 F15 retrieved 2026-08-22; F39 and A129 retrieved 2026-08-23|FSR04 FSR05 FSR06 FSR08 FSR09 FSR11 FSR12
SLO|SLO04|Every policy-required customer notice reaches the contractually accepted completion state before expiry|Durable notification intent to channel receipt or customer inbox completion; provider acceptance alone is not customer completion|Every eligible required intent reaches policy-accepted receipt/customer-inbox completion or a pre-deadline approved documented exception within 5 min and before expiry|Snapshot when a durable intent is created as required under versioned jurisdiction consent template and expiry policy; a later expiry or missed notice remains eligible and bad for the window|Budgeted service bad: no accepted completion or pre-deadline approved exception by 5 min/before expiry, including owned breaks and expired missed notices. Latency population: every snapshotted intent with non-completions censored and latency-bad. Safety counters: missing required intent, duplicate business action, undocumented exception|completed_service_good divided by intent_snapshot_eligible; latency_bad divided by the same eligible intents using actual or censored completion time; safety counters separate|Per channel product jurisdiction template version and urgency|rolling 28 days plus 15 min symptom window|Inference: 99.00 percent and p99 at most 5 min; unvalidated planning scenario|Only a pre-obligation product window or consent state can prevent eligibility; expiry after obligation and missed notices are never excluded|1.00 percent applies only to budgeted completion/latency; missing required intent duplicate action and undocumented exception have threshold zero|Durable intent store provider receipt customer inbox state and exception register|Notification owner with Compliance for mandatory notices|BRN01 BRN02 for budgeted service/latency; immediate safety interrupt outside budget; never retry expired one-time code|Every eligible intent maps to accepted completion or approved exception; authority unchanged|Provider says accepted while customer/business contract remains incomplete|Inference: C117 C119; F14 F15 retrieved 2026-08-22; F39 and A131 retrieved 2026-08-23|FSR07 FSR10 FSR11 FSR12
SLO|SLO05|Independent controls close each reconciliation window with no unexplained financial discrepancy|Manifested half-open UTC window across orders executions obligations provider evidence and ledger exact units|Every eligible scheduled window closes clean by 02:00 UTC next day with zero unexplained break|Snapshot every scheduled product currency instrument provider and adjacent-window obligation before processing; deferral or owned break cannot remove it|Non-budget deadline bad: scheduled window not closed by deadline, including named owned breaks until VERIFIED and CLOSED. Safety counters: monetary quantity identity/version break, imbalance, duplicate fill, missing posting, unexplained provider difference|on_time_clean divided by scheduled_snapshot_eligible for planning latency reporting; every incomplete window remains latency-bad and censored through window end; safety counters separate and determine clean closure|Per legal entity product currency instrument provider and UTC half-open window|daily window plus rolling 28-day control view|Inference: 100 percent clean closure by 02:00 UTC; unvalidated planning scenario|No silent exclusion; Compliance may defer closure only by opening a named break with owner and deadline counted bad|No availability allowance authorizes a safety break; all safety counters threshold zero; the planning latency ratio cannot make an unclean window good|Signed manifests exact-unit control totals break lifecycle and independent approval|Ledger operations and independent Reconciliation owner|BRN00 non-budget deadline and safety path; normalized multi-window burn does not apply at target 1|Original and adjacent windows balance; provider evidence agrees; two-person VERIFIED then CLOSED|A retry clears a metric while an exact amount or identity remains unexplained|Inference: C117; F08 F14 F15 F17 retrieved 2026-08-22|FSR02 FSR03 FSR04 FSR06 FSR07 FSR08 FSR09 FSR11 FSR12
SLO|SLO06|Authorized investigators can retrieve complete named evidence for an approved audit assertion|Evidence manifest to named business records application audit and configured CloudTrail scope; integrity does not imply completeness|Every eligible approved request returns every named manifest item and validates integrity within 15 min|Snapshot at approval inside declared retention/legal-hold policy; later selector gaps, access incidents, or owned breaks cannot remove the request|Budgeted service bad: complete authorized result absent after 15 min, including owned breaks until completion. Latency population: every snapshotted request with incomplete retrieval censored and latency-bad. Safety counters: missing manifest item, selector/Region gap, integrity failure, unauthorized access|complete_service_good divided by request_snapshot_eligible; latency_bad divided by the same eligible requests using actual or censored retrieval time; safety counters separate|Per assertion evidence class account Region legal entity and retention cohort|rolling 90 days plus immediate integrity and access alerts|Inference: 99.90 percent and p99 at most 15 min; unvalidated planning scenario|Out-of-scope or expired request only with Legal owner decision; Audit owner monitors rejection and deletion volume|0.10 percent applies only to budgeted retrieval service/latency; unauthorized access integrity failure and known completeness gap have threshold zero|Evidence catalog manifests application records CloudTrail trails or stores validation results and access log|Audit platform owner with Legal retention owner|BRN01 BRN02 for retrieval service/latency; immediate access integrity selector and manifest safety interrupt outside budget|Manifest population equals query result; checksums validate; sampled telemetry is not substituted|CloudTrail or Object Lock is green while required application evidence is absent|Inference: C109 C117 C122; F14 F15 retrieved 2026-08-22; F39 and A135 retrieved 2026-08-23|FSR02 FSR03 FSR05 FSR06 FSR07 FSR09 FSR10 FSR11 FSR12

id	outcome	boundary	good	eligible	bad	formula	scope	window	target	exclusions	budget	source	owner	burn	proof	falsifier	governance	fsr_routes
SLO01	A customer receives one durable acceptance or deterministic rejection for one logical order	Order command record and authoritative order lookup observed at API edge; transport progress is not acceptance	Every eligible command has one matching durable accepted or deterministic valid product/policy rejection within 2 s and one fingerprint maps to one order	Snapshot at authenticated syntactically valid non-test admission before the product/policy decision; accepted and deterministic valid rejections remain eligible for the whole window	Budgeted service bad: no durable deterministic outcome by 2 s, including an owned break until completion. Latency population: every eligible admission; incomplete outcomes are deadline-censored and latency-bad, never absent. Safety counters: lost accepted command, mismatched fingerprint, duplicate logical order	service_good divided by admission_snapshot_eligible; latency_bad divided by the same eligible population, with actual completion latency or at least window-end censoring for incomplete outcomes; safety counters reported separately	Per product region client class and tenant fairness cohort	rolling 28 days plus 5 min symptom window	Inference: 99.90 percent and p99 at most 2 s; unvalidated planning scenario	Only pre-approved test traffic or scheduled unavailable product window; Product owner approves and SRE owner monitors exclusion ratio	0.10 percent applies only to budgeted service/latency bad; safety counters have threshold zero and never consume availability budget	Command store transitions joined to API receipts and accepted-order manifest	Order API owner	BRN01 BRN02 for budgeted service/latency; immediate safety interrupt outside budget	One fingerprint one order one durable result; accepted manifest has no gap	A load test or production baseline cannot meet target without denominator manipulation	Inference: C117; F14 F15 F16 retrieved 2026-08-22; F39 retrieved 2026-08-23	FSR01 FSR02 FSR03 FSR08 FSR11 FSR12
SLO02	An accepted order's execution facts reach each required durable consumer without changing execution authority	Execution or matcher authority to consumer inbox or governed open break; portfolio and notice are not execution authority	Required consumer durably records source execution identity and version within 5 s; opening or owning a break is not good and remains bad until the consumer outcome completes	Snapshot when execution authority appends an execution whose versioned contract requires that consumer; later route, expiry, break, or configuration changes cannot remove it from the window	Budgeted service bad: required durable consumer record absent after 5 s, including owned breaks until completion. Latency population: every snapshotted obligation with incomplete outcomes deadline-censored and latency-bad. Safety counters: lost required fact, unexplained duplicate effect, unresolved stale/skipped version	service_good divided by obligation_snapshot_eligible; latency_bad divided by the same eligible obligations using actual or censored latency; each safety counter is separate	Per consumer architecture partition and priority lane	rolling 28 days plus 5 min symptom window	Inference: 99.90 percent and p99 at most 5 s; unvalidated planning scenario	Governed consumer not-required flag approved by Domain owner before event; Messaging owner monitors excluded volume	0.10 percent applies only to service/latency bad; lost fact duplicate effect and unresolved version safety counters have threshold zero	Execution journal or durable authority joined to outbox receipt and consumer inbox	Execution and messaging owners	BRN01 BRN02 for budgeted service/latency; immediate safety interrupt outside budget	Authority and inbox manifests balance by execution ID and source version	Replay or fan-out produces an effect twice or hides a required consumer	Inference: C117 C118; F14 F15 F16 retrieved 2026-08-22; F39 F40 retrieved 2026-08-23	FSR02 FSR03 FSR04 FSR05 FSR06 FSR11 FSR12
SLO03	A customer portfolio view states an as-of time and converges to recovered order execution and ledger authorities	Versioned projection watermark compared with authority manifests; projection never authorizes cash securities or corrections	Every eligible account observation includes required source versions through an authority watermark no older than 60 s	Snapshot each supported account observation obligation when an authoritative change is admitted; rebuild, account inactivity, or an owned gap cannot remove it from the window	Budgeted service bad: freshness older than 60 s or incomplete observation, including owned gaps until repaired. Latency population: every snapshotted observation with incomplete results censored and latency-bad. Safety counters: wrong exact amount, missing as-of, or derived state authorizes finance	fresh_service_good divided by observation_snapshot_eligible; freshness_latency_bad divided by the same eligible observations using actual or censored age; safety counters separate	Per tenant account build ID and source partition	rolling 28 days plus 5 min symptom window	Inference: 99.50 percent and p99 freshness at most 60 s; unvalidated planning scenario	Approved unavailable read product window only; Product owner approves and Projection owner monitors excluded accounts	0.50 percent applies only to budgeted freshness; wrong totals missing as-of and unauthorized projection use have threshold zero	Projection manifest and watermark joined to orders executions postings and balances in exact units	Projection owner with Domain owner for authority discrepancy	BRN01 BRN02 for budgeted freshness; immediate safety interrupt outside budget	No gaps; exact control totals and watermark match; vNext manifest approved before cutover	A backfill matches counts but not quantities exact values or source versions	Inference: C117 C119; F14 F15 retrieved 2026-08-22; F39 and A129 retrieved 2026-08-23	FSR04 FSR05 FSR06 FSR08 FSR09 FSR11 FSR12
SLO04	Every policy-required customer notice reaches the contractually accepted completion state before expiry	Durable notification intent to channel receipt or customer inbox completion; provider acceptance alone is not customer completion	Every eligible required intent reaches policy-accepted receipt/customer-inbox completion or a pre-deadline approved documented exception within 5 min and before expiry	Snapshot when a durable intent is created as required under versioned jurisdiction consent template and expiry policy; a later expiry or missed notice remains eligible and bad for the window	Budgeted service bad: no accepted completion or pre-deadline approved exception by 5 min/before expiry, including owned breaks and expired missed notices. Latency population: every snapshotted intent with non-completions censored and latency-bad. Safety counters: missing required intent, duplicate business action, undocumented exception	completed_service_good divided by intent_snapshot_eligible; latency_bad divided by the same eligible intents using actual or censored completion time; safety counters separate	Per channel product jurisdiction template version and urgency	rolling 28 days plus 15 min symptom window	Inference: 99.00 percent and p99 at most 5 min; unvalidated planning scenario	Only a pre-obligation product window or consent state can prevent eligibility; expiry after obligation and missed notices are never excluded	1.00 percent applies only to budgeted completion/latency; missing required intent duplicate action and undocumented exception have threshold zero	Durable intent store provider receipt customer inbox state and exception register	Notification owner with Compliance for mandatory notices	BRN01 BRN02 for budgeted service/latency; immediate safety interrupt outside budget; never retry expired one-time code	Every eligible intent maps to accepted completion or approved exception; authority unchanged	Provider says accepted while customer/business contract remains incomplete	Inference: C117 C119; F14 F15 retrieved 2026-08-22; F39 and A131 retrieved 2026-08-23	FSR07 FSR10 FSR11 FSR12
SLO05	Independent controls close each reconciliation window with no unexplained financial discrepancy	Manifested half-open UTC window across orders executions obligations provider evidence and ledger exact units	Every eligible scheduled window closes clean by 02:00 UTC next day with zero unexplained break	Snapshot every scheduled product currency instrument provider and adjacent-window obligation before processing; deferral or owned break cannot remove it	Non-budget deadline bad: scheduled window not closed by deadline, including named owned breaks until VERIFIED and CLOSED. Safety counters: monetary quantity identity/version break, imbalance, duplicate fill, missing posting, unexplained provider difference	on_time_clean divided by scheduled_snapshot_eligible for planning latency reporting; every incomplete window remains latency-bad and censored through window end; safety counters separate and determine clean closure	Per legal entity product currency instrument provider and UTC half-open window	daily window plus rolling 28-day control view	Inference: 100 percent clean closure by 02:00 UTC; unvalidated planning scenario	No silent exclusion; Compliance may defer closure only by opening a named break with owner and deadline counted bad	No availability allowance authorizes a safety break; all safety counters threshold zero; the planning latency ratio cannot make an unclean window good	Signed manifests exact-unit control totals break lifecycle and independent approval	Ledger operations and independent Reconciliation owner	BRN00 non-budget deadline and safety path; normalized multi-window burn does not apply at target 1	Original and adjacent windows balance; provider evidence agrees; two-person VERIFIED then CLOSED	A retry clears a metric while an exact amount or identity remains unexplained	Inference: C117; F08 F14 F15 F17 retrieved 2026-08-22	FSR02 FSR03 FSR04 FSR06 FSR07 FSR08 FSR09 FSR11 FSR12
SLO06	Authorized investigators can retrieve complete named evidence for an approved audit assertion	Evidence manifest to named business records application audit and configured CloudTrail scope; integrity does not imply completeness	Every eligible approved request returns every named manifest item and validates integrity within 15 min	Snapshot at approval inside declared retention/legal-hold policy; later selector gaps, access incidents, or owned breaks cannot remove the request	Budgeted service bad: complete authorized result absent after 15 min, including owned breaks until completion. Latency population: every snapshotted request with incomplete retrieval censored and latency-bad. Safety counters: missing manifest item, selector/Region gap, integrity failure, unauthorized access	complete_service_good divided by request_snapshot_eligible; latency_bad divided by the same eligible requests using actual or censored retrieval time; safety counters separate	Per assertion evidence class account Region legal entity and retention cohort	rolling 90 days plus immediate integrity and access alerts	Inference: 99.90 percent and p99 at most 15 min; unvalidated planning scenario	Out-of-scope or expired request only with Legal owner decision; Audit owner monitors rejection and deletion volume	0.10 percent applies only to budgeted retrieval service/latency; unauthorized access integrity failure and known completeness gap have threshold zero	Evidence catalog manifests application records CloudTrail trails or stores validation results and access log	Audit platform owner with Legal retention owner	BRN01 BRN02 for retrieval service/latency; immediate access integrity selector and manifest safety interrupt outside budget	Manifest population equals query result; checksums validate; sampled telemetry is not substituted	CloudTrail or Object Lock is green while required application evidence is absent	Inference: C109 C117 C122; F14 F15 retrieved 2026-08-22; F39 and A135 retrieved 2026-08-23	FSR02 FSR03 FSR05 FSR06 FSR07 FSR09 FSR10 FSR11 FSR12

The canonical rows above are rendered into the table during authoring and checked byte-for-byte by the gate. Safety is an independent interrupt:

Safety boundary	Threshold
availability_budget_never_authorizes=wrong_financial_outcome	threshold=zero_unresolved

Model details · slo safety

SLO_SAFETY|availability_budget_never_authorizes=wrong_financial_outcome|threshold=zero_unresolved

Two independent event-unit examples make the budget arithmetic reviewable. For an eligible population N, target ratio T, and observed bad count B: allowed_bad = N × (1 - T), remaining = allowed_bad - B, and consumed = B / allowed_bad. No latency percentile is mixed into those ratios.

ID	Eligible population	Target ratio	Observed bad	Allowed bad	Remaining	Burn
CAL01	eligible=2000000	target=0.999	bad=700	allowed_bad=2000	remaining=1300	burn=0.3500
CAL02	eligible=40000	target=0.99	bad=120	allowed_bad=400	remaining=280	burn=0.3000

Model details · slo calc

SLO_CALC|CAL01|eligible=2000000|target=0.999|bad=700|allowed_bad=2000|remaining=1300|burn=0.3500
SLO_CALC|CAL02|eligible=40000|target=0.99|bad=120|allowed_bad=400|remaining=280|burn=0.3000

CAL01: eligible=2000000 events; target=0.999; allowed_bad=2000 events; observed_bad=700 events; remaining=1300 events; consumed=35.0%.

CAL02: eligible=40000 events; target=0.99; allowed_bad=400 events; observed_bad=120 events; remaining=280 events; consumed=30.0%.

Model details · task11 burn

BURN|BRN00|Non-budget deadline and financial-safety path|No normalized burn calculation because target is exactly 1 and allowed error rate is zero|Any eligible window incomplete at 02:00 UTC or any unresolved financial break triggers|Every scheduled snapshot obligation; no minimum count gate|Missing manifest or measurement is an open break never zero or good|Page and freeze affected scope at first missed deadline or break; ticket remains open until VERIFIED and CLOSED|Inject one missed deadline and one exact-unit break; falsified if either is averaged gated or divided by zero|Inference: zero-error deadline path from C117; F14 F15 retrieved 2026-08-22; F39 retrieved 2026-08-23
BURN|BRN01|5m and 1h fast pair|burn(W) = (budgeted_bad(W) / eligible_snapshot(W)) / (1 - target); compute service and latency series separately|Both 5m and 1h burn at least 14.4|At least 100 eligible observations in each window; otherwise ratio is not evaluated|Missing numerator denominator or authority-manifest feed is not zero; mark measurement gap and page when authority admits traffic, while synthetic probes and safety interrupts remain active|Page the SLO owner, freeze release and replay expansion, contain via OPMAP; safety counters bypass this pair and page immediately|Backtest incident corpus and inject 14.4 burn at minimum traffic; falsified if a material budget incident is missed or pages are noisy|Inference: planning threshold and gate from C117 and F39 retrieved 2026-08-23
BURN|BRN02|6h and 3d slow pair|burn(W) = (budgeted_bad(W) / eligible_snapshot(W)) / (1 - target); compute service and latency series separately|Both 6h and 3d burn at least 1.0|At least 1000 eligible observations in each window; otherwise use ticketed sparse-SLO review and never treat missing as good|Missing data opens a measurement ticket and release hold when authority manifests show obligations; safety interrupts continue without a count gate|Open owned ticket, hold release until population and cause are understood, assign product/service owner; safety counters bypass this pair|Backtest 90 days and inject sustained 1.0 burn; falsified if budget exhaustion proceeds without hold or sparse traffic is classified healthy|Inference: planning threshold and gate from C117 and F39 retrieved 2026-08-23

id	pair	formula	threshold	gate	missing	action	backtest	governance
BRN00	Non-budget deadline and financial-safety path	No normalized burn calculation because target is exactly 1 and allowed error rate is zero	Any eligible window incomplete at 02:00 UTC or any unresolved financial break triggers	Every scheduled snapshot obligation; no minimum count gate	Missing manifest or measurement is an open break never zero or good	Page and freeze affected scope at first missed deadline or break; ticket remains open until VERIFIED and CLOSED	Inject one missed deadline and one exact-unit break; falsified if either is averaged gated or divided by zero	Inference: zero-error deadline path from C117; F14 F15 retrieved 2026-08-22; F39 retrieved 2026-08-23
BRN01	5m and 1h fast pair	burn(W) = (budgeted_bad(W) / eligible_snapshot(W)) / (1 - target); compute service and latency series separately	Both 5m and 1h burn at least 14.4	At least 100 eligible observations in each window; otherwise ratio is not evaluated	Missing numerator denominator or authority-manifest feed is not zero; mark measurement gap and page when authority admits traffic, while synthetic probes and safety interrupts remain active	Page the SLO owner, freeze release and replay expansion, contain via OPMAP; safety counters bypass this pair and page immediately	Backtest incident corpus and inject 14.4 burn at minimum traffic; falsified if a material budget incident is missed or pages are noisy	Inference: planning threshold and gate from C117 and F39 retrieved 2026-08-23
BRN02	6h and 3d slow pair	burn(W) = (budgeted_bad(W) / eligible_snapshot(W)) / (1 - target); compute service and latency series separately	Both 6h and 3d burn at least 1.0	At least 1000 eligible observations in each window; otherwise use ticketed sparse-SLO review and never treat missing as good	Missing data opens a measurement ticket and release hold when authority manifests show obligations; safety interrupts continue without a count gate	Open owned ticket, hold release until population and cause are understood, assign product/service owner; safety counters bypass this pair	Backtest 90 days and inject sustained 1.0 burn; falsified if budget exhaustion proceeds without hold or sparse traffic is classified healthy	Inference: planning threshold and gate from C117 and F39 retrieved 2026-08-23

Business-to-technical operating map

The SLO explains the harm; the operating map locates who can act. FSR is a failure from the reliability chapter, RBK its runbook, and DR a recovery tier. RSP and INV refer to the trading responsibilities and invariants. Follow a symptom to its cause signals and owner, then read the proof column before declaring the incident resolved.

Each FSR appears once. The SLO rows carry the reverse edges. RBK and DR identify reviewed operating procedures; ARCA/ARCB/ARCC, RSP, and INV are references to upstream authorities, not redefinitions.

Model details · task11 opmap

OPMAP|FSR01|Client or API timeout/disconnect before response|SLO01|unknown acceptance age and accepted-without-response count|API Gateway Latency and 5XXError; Lambda errors/timeouts; command IN_PROGRESS age; exact source route: Inference: diagnostic signal selection from C119; A128 A139 retrieved 2026-08-23|Page when any lost or mismatched accepted command or unknown older than 2 min|Order API owner|RBK01 DR01|Return pending and lookup token; prohibit a second logical order|Resolve fingerprint command order and outbox under original identity|One fingerprint one order one durable response; accepted manifest balances|Client caches and network retries can outlive the window|ARCA ARCB ARCC|RSP01 RSP02 INV01 INV08 INV09
OPMAP|FSR02|Producer rejection or ambiguous acknowledgement|SLO01 SLO02 SLO05 SLO06|oldest unsent outbox and accepted event without required receipt|EventBridge FailedEntryCount entry errors target delivery failures and downstream receipt gap; exact source route: Inference: diagnostic signal selection from C119; A140 retrieved 2026-08-23; EventBridge DLQ A81 retrieved 2026-08-22|Page on accepted fact without receipt past 2 min or any unresolvable producer result|Messaging owner and order owner|RBK02 DR03|Keep outbox pending; circuit publisher lane; do not alter authority|Republish original ID after explicit failure or reconcile unknown before retry|Outbox manifest equals downstream inbox receipt or named open break|Producer success cannot prove routing or consumer effect|ARCA ARCB ARCC|RSP01 RSP03 RSP04 RSP05 RSP06 RSP07 RSP08 RSP09 RSP11 RSP12 RSP13 RSP14 INV08 INV09
OPMAP|FSR03|Batch API partially accepts records|SLO01 SLO02 SLO05 SLO06|attempted minus explicit success failure and resolved unknown|Per-entry FailedEntryCount missing result manifest imbalance and receipt gaps; exact source route: Inference: diagnostic signal selection from C119; A140 retrieved 2026-08-23|Page on any unowned unknown entry or manifest imbalance|Producer team|RBK02 DR03|Freeze blind whole-batch retry and retain original manifest|Retry explicit failures only; reconcile unknown entries by original identity|Attempted equals explicit success plus explicit failure plus resolved unknown|Per-entry API acknowledgement still does not prove downstream effect|ARCA ARCB ARCC|RSP01 RSP12 RSP13 RSP14 INV08 INV09
OPMAP|FSR04|Delivery is delayed duplicated or out of source order|SLO02 SLO03 SLO05|duplicate effects version gaps stale account count and projection lag|SQS oldest age; Kinesis IteratorAgeMilliseconds; inbox duplicate hits; source-version gaps; exact source route: Inference: diagnostic signal selection from C119; A141 retrieved 2026-08-23; Kinesis A99 retrieved 2026-08-22|Page on duplicate business effect or wrong amount; freshness page on sustained gaps|Projection and domain owners|RBK05 DR03 DR04|Park gaps reject stale versions and keep old view with as-of marker|Fetch missing authority range or rebuild vNext with side effects suppressed|Every version applied once or superseded; totals and watermark match|Aggregate lag can hide one tenant key or priority lane|ARCA ARCB ARCC|RSP10 RSP11 RSP12 RSP13 RSP14 INV08 INV09 INV10
OPMAP|FSR05|Poison or incompatible schema event repeatedly fails|SLO02 SLO03 SLO06|quarantined event age ordered-lane block and schema error count|Receive count validation class Kinesis iterator age source sequence and consumer version; exact source route: Inference: diagnostic signal selection from C119; Lambda A139 retrieved 2026-08-23; Flink A89 and MSK A90 retrieved 2026-08-22|Page immediately on ordered lane block or nonretryable required event|Schema and consuming domain owners|RBK04 DR03|Quarantine exact payload and isolate key; never drop silently|Canary fixed consumer or governed transform with new lineage|Counts versions gaps and effects reconcile against source authority|Retention can expire before repair and schema-valid data can remain semantically unsafe|ARCA ARCB ARCC|RSP10 RSP11 RSP12 RSP13 RSP14 INV08 INV09 INV10
OPMAP|FSR06|Handler timeout crash or lost acknowledgement|SLO02 SLO03 SLO05 SLO06|oldest unresolved inbox lease duplicate delivery and target-version gap|Lambda Errors Duration Throttles; queue age; checkpoint lag; dependency latency; exact source route: Inference: diagnostic signal selection from C119; Lambda A139 SQS A141 retrieved 2026-08-23|Page on missing required effect or expired lease; cause alarm diagnoses saturation|Consumer and dependency owners|RBK03 DR03|Cap concurrency isolate dependency preserve record and protected state|Take over expired lease only after evidence; replay original ID|Inbox COMPLETED and protected target version or external receipt proves one effect|A successful invocation metric cannot prove the protected commit|ARCA ARCB ARCC|RSP10 RSP11 RSP12 RSP13 RSP14 INV08 INV09 INV10
OPMAP|FSR07|Exchange bank or custodian call times out after possible invocation|SLO04 SLO05 SLO06|provider receipt gap pending-external age and reconciliation break|Timeout status lookup callback age circuit state and provider quota; exact source route: Inference: provider callback and receipt signals are local contract evidence, not an AWS completion claim; C117; F14 F15 retrieved 2026-08-22|Page on ambiguous effect beyond product threshold or conflicting provider state|Trading or payments operations|RBK06 RBK07 DR02|Open circuit for optional work preserve intent and block conflict|Lookup by provider request ID then forward-complete reverse or correct under dual control|Provider receipt intent posting and customer state agree|Provider availability and statements remain independently owned|ARCA ARCB ARCC|RSP05 RSP07 RSP08 RSP11 INV07 INV08 INV09
OPMAP|FSR08|DynamoDB conditional contention throttle or one hot key|SLO01 SLO03 SLO05|busy or pending command age conflict rate and exact-control break|DynamoDB ThrottledRequests throttle-event dimensions SystemErrors latency and hot-key contributor; exact source route: Inference: diagnostic signal selection from C119; A129 retrieved 2026-08-23|Page on authority latency or correctness symptom; ticket diagnosed capacity pressure|Owning bounded context and capacity on-call|RBK03 RBK07 DR01 DR02|Per-key bulkhead admission control and reserved authority capacity|Re-read authority; retry only throttle; migrate key model through ordered versioned cutover|Conditional version advances once and invariants plus ledger totals hold|Aggregate capacity can be green while one key is infeasible|ARCA ARCB ARCC|RSP01 RSP03 RSP04 RSP09 RSP10 INV01 INV02 INV05 INV06 INV09 INV10
OPMAP|FSR09|Projection gap lag failed rebuild or stale cutover|SLO03 SLO05 SLO06|stale account count missing version exact-total difference and build lag|Source versus target counts values watermark alias build ID Firehose freshness and Flink or MSK consumer lag if present; exact source route: Inference: diagnostic signal selection from C119; Firehose A131 retrieved 2026-08-23; Flink A89 MSK A90 retrieved 2026-08-22|Page on wrong value unauthorized projection use or unsafe cutover; freshness page otherwise|Projection owner and domain approver|RBK05 DR04|Keep old projection with as-of banner pause cutover and suppress rebuild effects|Backfill isolated vNext catch up validate then conditional alias switch|Manifest complete no gaps exact totals match and rollback target retained|A green rebuild job or object count does not prove semantic equivalence|ARCA ARCB ARCC|RSP10 RSP14 INV08 INV09 INV10
OPMAP|FSR10|Notification endpoint or client delivery fails|SLO04 SLO06|required intent age missing receipt and incomplete customer inbox state|SNS delivery failures provider status expiry channel quota and projection gap; exact source route: Inference: diagnostic signal selection from C119; SNS A142 retrieved 2026-08-23|Page on required-notice breach; ticket slow budget; dashboard optional notices|Notification owner and Compliance|RBK06 DR05|Isolate channel from command path and preserve durable intent|Regenerate only policy-valid notice from authority; never repeat business action|Every eligible intent has accepted completion or approved exception|Provider acceptance and device delivery can differ|ARCA ARCB ARCC|RSP11 INV08 INV09 INV10
OPMAP|FSR11|Backlog overload retry storm or dependency saturation|SLO01 SLO02 SLO03 SLO04 SLO05 SLO06|business age burn rejection wait stale cohorts and unresolved accepted count|SQS oldest age not depth alone; Kinesis iterator age; Lambda throttles; dependency saturation; net drain; exact source route: Inference: diagnostic signal selection from C119; Lambda A139 EventBridge A140 SQS A141 retrieved 2026-08-23; Kinesis A99 retrieved 2026-08-22|Page on customer or correctness symptom; cause alarms page only when immediate action exists|Incident commander service and dependency owners|RBK03 RBK07 DR01 DR02 DR03|Shed optional work cap replay open circuit and reserve authority lanes|Drain only with positive measured spare capacity; reconcile expired dropped and deferred work|Age below objective no starvation every admitted command resolved and controls clean|Replay competes with live traffic and can exceed retention or provider quotas|ARCA ARCB ARCC|RSP01 RSP02 RSP03 RSP04 RSP05 RSP06 RSP07 RSP08 RSP09 RSP10 RSP11 RSP12 RSP13 RSP14 INV08 INV09 INV10
OPMAP|FSR12|Region loss or unsafe failover|SLO01 SLO02 SLO03 SLO04 SLO05 SLO06|business probe failure writer-epoch conflict recovery-point age and manifest gaps|Regional health replication lag KMS and dependency readiness DNS stale-client probes and replay backlog; exact source route: Inference: regional business probes and authority manifests govern failover; C105 C106; A119 A120 A121 retrieved 2026-08-22|Page regional business failure or any second writer; RTO clock is not the RPO measurement|Incident commander plus command ledger platform external and compliance owners|RBK08 DR01 DR02 DR03 DR04 DR05|Stop writes fence old Region and withhold command routing|Recover authority first promote one epoch then replay rebuild and reconcile before unrestricted service|One active epoch measured RTO and RPO stale-client probes and financial totals pass|DNS caches long connections external providers and corruption survive topology failover|ARCA ARCB ARCC|RSP01 RSP02 RSP03 RSP04 RSP05 RSP06 RSP07 RSP08 RSP09 RSP10 RSP11 RSP12 RSP13 RSP14 INV01 INV02 INV03 INV04 INV05 INV06 INV07 INV08 INV09 INV10

id	failure	slo	symptom	causes	alarm	owner	runbook_dr	containment	repair	proof	residual	architecture	authority
FSR01	Client or API timeout/disconnect before response	SLO01	unknown acceptance age and accepted-without-response count	API Gateway Latency and 5XXError; Lambda errors/timeouts; command IN_PROGRESS age; exact source route: Inference: diagnostic signal selection from C119; A128 A139 retrieved 2026-08-23	Page when any lost or mismatched accepted command or unknown older than 2 min	Order API owner	RBK01 DR01	Return pending and lookup token; prohibit a second logical order	Resolve fingerprint command order and outbox under original identity	One fingerprint one order one durable response; accepted manifest balances	Client caches and network retries can outlive the window	ARCA ARCB ARCC	RSP01 RSP02 INV01 INV08 INV09
FSR02	Producer rejection or ambiguous acknowledgement	SLO01 SLO02 SLO05 SLO06	oldest unsent outbox and accepted event without required receipt	EventBridge FailedEntryCount entry errors target delivery failures and downstream receipt gap; exact source route: Inference: diagnostic signal selection from C119; A140 retrieved 2026-08-23; EventBridge DLQ A81 retrieved 2026-08-22	Page on accepted fact without receipt past 2 min or any unresolvable producer result	Messaging owner and order owner	RBK02 DR03	Keep outbox pending; circuit publisher lane; do not alter authority	Republish original ID after explicit failure or reconcile unknown before retry	Outbox manifest equals downstream inbox receipt or named open break	Producer success cannot prove routing or consumer effect	ARCA ARCB ARCC	RSP01 RSP03 RSP04 RSP05 RSP06 RSP07 RSP08 RSP09 RSP11 RSP12 RSP13 RSP14 INV08 INV09
FSR03	Batch API partially accepts records	SLO01 SLO02 SLO05 SLO06	attempted minus explicit success failure and resolved unknown	Per-entry FailedEntryCount missing result manifest imbalance and receipt gaps; exact source route: Inference: diagnostic signal selection from C119; A140 retrieved 2026-08-23	Page on any unowned unknown entry or manifest imbalance	Producer team	RBK02 DR03	Freeze blind whole-batch retry and retain original manifest	Retry explicit failures only; reconcile unknown entries by original identity	Attempted equals explicit success plus explicit failure plus resolved unknown	Per-entry API acknowledgement still does not prove downstream effect	ARCA ARCB ARCC	RSP01 RSP12 RSP13 RSP14 INV08 INV09
FSR04	Delivery is delayed duplicated or out of source order	SLO02 SLO03 SLO05	duplicate effects version gaps stale account count and projection lag	SQS oldest age; Kinesis IteratorAgeMilliseconds; inbox duplicate hits; source-version gaps; exact source route: Inference: diagnostic signal selection from C119; A141 retrieved 2026-08-23; Kinesis A99 retrieved 2026-08-22	Page on duplicate business effect or wrong amount; freshness page on sustained gaps	Projection and domain owners	RBK05 DR03 DR04	Park gaps reject stale versions and keep old view with as-of marker	Fetch missing authority range or rebuild vNext with side effects suppressed	Every version applied once or superseded; totals and watermark match	Aggregate lag can hide one tenant key or priority lane	ARCA ARCB ARCC	RSP10 RSP11 RSP12 RSP13 RSP14 INV08 INV09 INV10
FSR05	Poison or incompatible schema event repeatedly fails	SLO02 SLO03 SLO06	quarantined event age ordered-lane block and schema error count	Receive count validation class Kinesis iterator age source sequence and consumer version; exact source route: Inference: diagnostic signal selection from C119; Lambda A139 retrieved 2026-08-23; Flink A89 and MSK A90 retrieved 2026-08-22	Page immediately on ordered lane block or nonretryable required event	Schema and consuming domain owners	RBK04 DR03	Quarantine exact payload and isolate key; never drop silently	Canary fixed consumer or governed transform with new lineage	Counts versions gaps and effects reconcile against source authority	Retention can expire before repair and schema-valid data can remain semantically unsafe	ARCA ARCB ARCC	RSP10 RSP11 RSP12 RSP13 RSP14 INV08 INV09 INV10
FSR06	Handler timeout crash or lost acknowledgement	SLO02 SLO03 SLO05 SLO06	oldest unresolved inbox lease duplicate delivery and target-version gap	Lambda Errors Duration Throttles; queue age; checkpoint lag; dependency latency; exact source route: Inference: diagnostic signal selection from C119; Lambda A139 SQS A141 retrieved 2026-08-23	Page on missing required effect or expired lease; cause alarm diagnoses saturation	Consumer and dependency owners	RBK03 DR03	Cap concurrency isolate dependency preserve record and protected state	Take over expired lease only after evidence; replay original ID	Inbox COMPLETED and protected target version or external receipt proves one effect	A successful invocation metric cannot prove the protected commit	ARCA ARCB ARCC	RSP10 RSP11 RSP12 RSP13 RSP14 INV08 INV09 INV10
FSR07	Exchange bank or custodian call times out after possible invocation	SLO04 SLO05 SLO06	provider receipt gap pending-external age and reconciliation break	Timeout status lookup callback age circuit state and provider quota; exact source route: Inference: provider callback and receipt signals are local contract evidence, not an AWS completion claim; C117; F14 F15 retrieved 2026-08-22	Page on ambiguous effect beyond product threshold or conflicting provider state	Trading or payments operations	RBK06 RBK07 DR02	Open circuit for optional work preserve intent and block conflict	Lookup by provider request ID then forward-complete reverse or correct under dual control	Provider receipt intent posting and customer state agree	Provider availability and statements remain independently owned	ARCA ARCB ARCC	RSP05 RSP07 RSP08 RSP11 INV07 INV08 INV09
FSR08	DynamoDB conditional contention throttle or one hot key	SLO01 SLO03 SLO05	busy or pending command age conflict rate and exact-control break	DynamoDB ThrottledRequests throttle-event dimensions SystemErrors latency and hot-key contributor; exact source route: Inference: diagnostic signal selection from C119; A129 retrieved 2026-08-23	Page on authority latency or correctness symptom; ticket diagnosed capacity pressure	Owning bounded context and capacity on-call	RBK03 RBK07 DR01 DR02	Per-key bulkhead admission control and reserved authority capacity	Re-read authority; retry only throttle; migrate key model through ordered versioned cutover	Conditional version advances once and invariants plus ledger totals hold	Aggregate capacity can be green while one key is infeasible	ARCA ARCB ARCC	RSP01 RSP03 RSP04 RSP09 RSP10 INV01 INV02 INV05 INV06 INV09 INV10
FSR09	Projection gap lag failed rebuild or stale cutover	SLO03 SLO05 SLO06	stale account count missing version exact-total difference and build lag	Source versus target counts values watermark alias build ID Firehose freshness and Flink or MSK consumer lag if present; exact source route: Inference: diagnostic signal selection from C119; Firehose A131 retrieved 2026-08-23; Flink A89 MSK A90 retrieved 2026-08-22	Page on wrong value unauthorized projection use or unsafe cutover; freshness page otherwise	Projection owner and domain approver	RBK05 DR04	Keep old projection with as-of banner pause cutover and suppress rebuild effects	Backfill isolated vNext catch up validate then conditional alias switch	Manifest complete no gaps exact totals match and rollback target retained	A green rebuild job or object count does not prove semantic equivalence	ARCA ARCB ARCC	RSP10 RSP14 INV08 INV09 INV10
FSR10	Notification endpoint or client delivery fails	SLO04 SLO06	required intent age missing receipt and incomplete customer inbox state	SNS delivery failures provider status expiry channel quota and projection gap; exact source route: Inference: diagnostic signal selection from C119; SNS A142 retrieved 2026-08-23	Page on required-notice breach; ticket slow budget; dashboard optional notices	Notification owner and Compliance	RBK06 DR05	Isolate channel from command path and preserve durable intent	Regenerate only policy-valid notice from authority; never repeat business action	Every eligible intent has accepted completion or approved exception	Provider acceptance and device delivery can differ	ARCA ARCB ARCC	RSP11 INV08 INV09 INV10
FSR11	Backlog overload retry storm or dependency saturation	SLO01 SLO02 SLO03 SLO04 SLO05 SLO06	business age burn rejection wait stale cohorts and unresolved accepted count	SQS oldest age not depth alone; Kinesis iterator age; Lambda throttles; dependency saturation; net drain; exact source route: Inference: diagnostic signal selection from C119; Lambda A139 EventBridge A140 SQS A141 retrieved 2026-08-23; Kinesis A99 retrieved 2026-08-22	Page on customer or correctness symptom; cause alarms page only when immediate action exists	Incident commander service and dependency owners	RBK03 RBK07 DR01 DR02 DR03	Shed optional work cap replay open circuit and reserve authority lanes	Drain only with positive measured spare capacity; reconcile expired dropped and deferred work	Age below objective no starvation every admitted command resolved and controls clean	Replay competes with live traffic and can exceed retention or provider quotas	ARCA ARCB ARCC	RSP01 RSP02 RSP03 RSP04 RSP05 RSP06 RSP07 RSP08 RSP09 RSP10 RSP11 RSP12 RSP13 RSP14 INV08 INV09 INV10
FSR12	Region loss or unsafe failover	SLO01 SLO02 SLO03 SLO04 SLO05 SLO06	business probe failure writer-epoch conflict recovery-point age and manifest gaps	Regional health replication lag KMS and dependency readiness DNS stale-client probes and replay backlog; exact source route: Inference: regional business probes and authority manifests govern failover; C105 C106; A119 A120 A121 retrieved 2026-08-22	Page regional business failure or any second writer; RTO clock is not the RPO measurement	Incident commander plus command ledger platform external and compliance owners	RBK08 DR01 DR02 DR03 DR04 DR05	Stop writes fence old Region and withhold command routing	Recover authority first promote one epoch then replay rebuild and reconcile before unrestricted service	One active epoch measured RTO and RPO stale-client probes and financial totals pass	DNS caches long connections external providers and corruption survive topology failover	ARCA ARCB ARCC	RSP01 RSP02 RSP03 RSP04 RSP05 RSP06 RSP07 RSP08 RSP09 RSP10 RSP11 RSP12 RSP13 RSP14 INV01 INV02 INV03 INV04 INV05 INV06 INV07 INV08 INV09 INV10

The reverse contract is explicit rather than inferred from a runbook title:

Model details · task11 rbkdr

RBKDR|RBK01|runbook|FSR01
RBKDR|RBK02|runbook|FSR02 FSR03
RBKDR|RBK03|runbook|FSR06 FSR08 FSR11
RBKDR|RBK04|runbook|FSR05
RBKDR|RBK05|runbook|FSR04 FSR09
RBKDR|RBK06|runbook|FSR07 FSR10
RBKDR|RBK07|runbook|FSR07 FSR08 FSR11
RBKDR|RBK08|runbook|FSR12
RBKDR|DR01|dr|FSR01 FSR08 FSR11 FSR12
RBKDR|DR02|dr|FSR07 FSR08 FSR11 FSR12
RBKDR|DR03|dr|FSR02 FSR03 FSR04 FSR05 FSR06 FSR11 FSR12
RBKDR|DR04|dr|FSR04 FSR09 FSR12
RBKDR|DR05|dr|FSR10 FSR12

id	type	fsr_routes
RBK01	runbook	FSR01
RBK02	runbook	FSR02 FSR03
RBK03	runbook	FSR06 FSR08 FSR11
RBK04	runbook	FSR05
RBK05	runbook	FSR04 FSR09
RBK06	runbook	FSR07 FSR10
RBK07	runbook	FSR07 FSR08 FSR11
RBK08	runbook	FSR12
DR01	dr	FSR01 FSR08 FSR11 FSR12
DR02	dr	FSR07 FSR08 FSR11 FSR12
DR03	dr	FSR02 FSR03 FSR04 FSR05 FSR06 FSR11 FSR12
DR04	dr	FSR04 FSR09 FSR12
DR05	dr	FSR10 FSR12

Model details · task11 service presence

SERVICE|SVC01|API Gateway and Lambda|present for command/query edges|absent from owned market pipeline; external authorities may expose it|present around matcher, absent inside match loop|ARCA/ARCC contracts retain serverless edges; ARCB owns RSP12-RSP14 pipeline only|Inference: architecture presence from reviewed ARCH rows; metrics C119; A128 A139 retrieved 2026-08-23
SERVICE|SVC02|EventBridge|present for semantic business distribution|absent from high-rate feed path|present around command/control/notification edges, absent inside matcher|Derived from outbox and serverless-surrounding contracts|Inference: service choice and metrics C119; A140 retrieved 2026-08-23; DLQ A81 retrieved 2026-08-22
SERVICE|SVC03|SQS and SNS|present for buffered consumers and notifications|absent from owned market-data lane|present around workflows/projections/notifications, absent inside matcher|RSP11 notification and async repair routes|Inference: service choice and metrics C119; A141 A142 retrieved 2026-08-23
SERVICE|SVC04|Kinesis|present when selected for projection transport; otherwise absent in favor of Streams|present as one allowed high-rate transport alternative|present only around matcher when selected; absent inside matcher|ARCH alternatives explicitly preserve service choice|Inference: transport choice from C49 C77; A99 retrieved 2026-08-22
SERVICE|SVC05|DynamoDB and Streams|present for authority/projection paths|absent from owned feed pipeline|present for serverless authority/projection paths, absent from match journal|ARCH authority and projection contracts|Inference: service choice and metrics C119; A129 retrieved 2026-08-23
SERVICE|SVC06|Step Functions|present for earned external workflows|absent from owned feed pipeline|present around matcher for earned workflows, absent inside matcher|External-effect workflow contract only|Inference: service choice and metrics C119; A130 retrieved 2026-08-23
SERVICE|SVC07|Firehose|present only when selected for audit landing; otherwise absent|present for buffered audit/destination delivery|present only for surrounding audit landing; absent inside matcher|ARCHB service palette and optional evidence landing|Inference: destination choice and metrics C119; A131 retrieved 2026-08-23
SERVICE|SVC08|Flink and MSK|absent|present when event-time state or Kafka contract is earned; otherwise absent|present only around matcher when Kafka transport is earned; absent as matcher authority|ARCHB/ARCC reject unearned stateful transport|Inference: service choice from C67 C68; A89 A90 retrieved 2026-08-22
SERVICE|SVC09|Long-lived matcher|absent|absent|present as fenced partitioned matching authority|ARCC alone owns deterministic book matching|Inference: reviewed ARCC local policy from C111; F09 retrieved 2026-08-22

id	service	arca	arcb	arcc	premise	governance
SVC01	API Gateway and Lambda	present for command/query edges	absent from owned market pipeline; external authorities may expose it	present around matcher, absent inside match loop	ARCA/ARCC contracts retain serverless edges; ARCB owns RSP12-RSP14 pipeline only	Inference: architecture presence from reviewed ARCH rows; metrics C119; A128 A139 retrieved 2026-08-23
SVC02	EventBridge	present for semantic business distribution	absent from high-rate feed path	present around command/control/notification edges, absent inside matcher	Derived from outbox and serverless-surrounding contracts	Inference: service choice and metrics C119; A140 retrieved 2026-08-23; DLQ A81 retrieved 2026-08-22
SVC03	SQS and SNS	present for buffered consumers and notifications	absent from owned market-data lane	present around workflows/projections/notifications, absent inside matcher	RSP11 notification and async repair routes	Inference: service choice and metrics C119; A141 A142 retrieved 2026-08-23
SVC04	Kinesis	present when selected for projection transport; otherwise absent in favor of Streams	present as one allowed high-rate transport alternative	present only around matcher when selected; absent inside matcher	ARCH alternatives explicitly preserve service choice	Inference: transport choice from C49 C77; A99 retrieved 2026-08-22
SVC05	DynamoDB and Streams	present for authority/projection paths	absent from owned feed pipeline	present for serverless authority/projection paths, absent from match journal	ARCH authority and projection contracts	Inference: service choice and metrics C119; A129 retrieved 2026-08-23
SVC06	Step Functions	present for earned external workflows	absent from owned feed pipeline	present around matcher for earned workflows, absent inside matcher	External-effect workflow contract only	Inference: service choice and metrics C119; A130 retrieved 2026-08-23
SVC07	Firehose	present only when selected for audit landing; otherwise absent	present for buffered audit/destination delivery	present only for surrounding audit landing; absent inside matcher	ARCHB service palette and optional evidence landing	Inference: destination choice and metrics C119; A131 retrieved 2026-08-23
SVC08	Flink and MSK	absent	present when event-time state or Kafka contract is earned; otherwise absent	present only around matcher when Kafka transport is earned; absent as matcher authority	ARCHB/ARCC reject unearned stateful transport	Inference: service choice from C67 C68; A89 A90 retrieved 2026-08-22
SVC09	Long-lived matcher	absent	absent	present as fenced partitioned matching authority	ARCC alone owns deterministic book matching	Inference: reviewed ARCC local policy from C111; F09 retrieved 2026-08-22

Service-boundary signal guide

• API Gateway and Lambda: API Gateway Latency includes gateway overhead while IntegrationLatency covers the backend interval; use Count, 4XXError, and 5XXError with the right stage/method dimensions. Lambda errors, throttles, concurrency, duration, iterator age, and destination failures diagnose the invocation boundary. Neither proves command commit (C119; A128 A139 retrieved 2026-08-23).
• EventBridge: observe per-entry producer results, target invocation failure, failure-to-send-to-DLQ, outbox age, archive/replay state, and downstream receipt. A bus metric never replaces the acceptance or receipt manifest (C119; A140 retrieved 2026-08-23; EventBridge DLQ A81 retrieved 2026-08-22).
• SQS/SNS: use oldest age, receive/redrive counts, terminal destinations, per-subscription delivery failures, and required-intent age. Queue depth alone cannot reveal age, fairness, poison head-of-line blocking, or financial effect (C119; A141 A142 retrieved 2026-08-23).
• Kinesis: iterator age, read/write throttles, per-consumer lag, hot partition key, checkpoint, source-version gap, and retention margin are cause signals. A low aggregate iterator age can hide a hot shard or key (C77; A99 retrieved 2026-08-22).
• DynamoDB/Streams: monitor ThrottledRequests with the documented table/operation dimensions plus read/write throttle events, SystemErrors, conditional conflict, consumed capacity, transaction reason, Stream iterator age, and authority SLI. A dimension mismatch can leave an alarm in insufficient data (C119, A129 retrieved 2026-08-23).
• Step Functions: distinguish execution failed, timed out, aborted, throttled, open execution count, task failure, callback age, and external receipt. Count metrics can be emitted with at-least-once or best-effort behavior, so workflow history and task receipts close a case (C119, A130 retrieved 2026-08-23).
• Firehose: destination success/error and data-freshness metrics, backup/error objects, and source/target manifests are distinct. One-minute aggregation may miss short bursts (C119, A131 retrieved 2026-08-23).
• Flink/MSK: checkpoint age/failure, consumer lag by partition, restart loop, late-event policy, state-store health, broker ISR/under-replication, and sink commit receipt matter only in architectures that include them. ARCA has no Flink/MSK; ARCB may use Flink for projection analytics; ARCC may use MSK or Kinesis around the matcher, never as the match authority (C67 C68; A89 A90 retrieved 2026-08-22).
• Long-lived matcher: observe ingress-admission rejection, journal append/flush, command-to-decision latency, book/mailbox depth by symbol, single-writer epoch, snapshot/replay position, execution publication gap, CPU saturation, GC/runtime pauses, and standby lag. ARCA and ARCB do not contain this component (Inference: C111; F09 retrieved 2026-08-22).

Correlation tracing and cardinality

W3C Trace Context standardizes traceparent/tracestate propagation; W3C Baggage carries application properties but explicitly creates privacy and security concerns. Both are diagnostic carriers, not durable business authority (C118, F27, F40, F41). Sampling may remove a trace. It must never remove an accepted-command receipt, execution identity, posting, reconciliation manifest, or audit record.

Model details · task11 identity

IDENTITY|request|API edge creates per transport attempt|New across retry and replay|Access log for diagnostic horizon only|HTTP header and structured log; never used as effect key|API edge validates syntax and clock relation only|Tokenized; not a metric dimension; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
IDENTITY|correlation|First business entry point creates conversation ID|Stable across related workflow and explicit retry; retained on replay|Command record event envelope and evidence index|Message metadata structured logs traces and workflow input|Command or workflow authority validates membership|Opaque random value; bounded query index not metric dimension; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
IDENTITY|causation|Producer names immediate parent command or event|Stable for the emitted child; preserved through replay|Outbox and event envelope|Message metadata and evidence store|Parent authority or durable event log validates edge|No raw payload or PII; detect missing parent; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
IDENTITY|command|Client or command API creates logical business request ID|Stable across all client retry and recovery replay|Atomic command idempotency record with fingerprint and result|API request command record outbox and downstream lineage|Command authority validates fingerprint and one-result mapping|High-cardinality structured evidence; never unbounded metric label; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
IDENTITY|event|Authoritative producer creates immutable event ID|Stable across delivery retry and replay; repair transform creates new ID plus lineage|Transactional outbox durable log and consumer inbox|Event envelope message metadata and manifests|Producer outbox and source authority validate identity and version|Opaque ID; aggregate duplicate rate in metrics; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
IDENTITY|order|Order authority creates after valid acceptance|Stable for lifecycle; cancel or replace links rather than reuses semantics|Order authority and downstream facts|Payload and durable evidence; tokenized in broad logs|Order authority validates lifecycle version|Break-glass lookup maps token to raw ID under Audit owner; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
IDENTITY|execution|Matcher or venue authority creates for each fill fact|Stable; bust or correct is a new linked fact|Execution journal venue report and posting lineage|Execution event and reconciliation evidence|Matcher journal or venue report validates|Never treat trace or portfolio update as execution identity; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
IDENTITY|account|Account authority creates governed identifier|Stable subject to governed migration; replay preserves|Account authority reservations ledger and evidence index|Tokenized application context; raw only in restricted stores|Account authority validates tenant ownership|Raw account numbers prohibited in baggage logs and metric dimensions; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
IDENTITY|workflow|Durable coordinator creates process instance|Stable across task retries; redrive policy records new attempt lineage|Workflow state and business process authority|Workflow metadata tasks and receipts|Coordinator plus domain authority validate process and effects|Do not infer downstream exactly once from workflow ID; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
IDENTITY|source_version|Single authoritative writer assigns per aggregate sequence version and epoch|Stable on replay; correction appends next version|Authority journal or versioned state outbox and inbox|Event envelope checkpoint and projection manifest|Authority validates monotonic version and active writer epoch|Use bounded gap counts in metrics and full values in evidence; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
IDENTITY|replay_build|Operator tooling creates signed replay manifest ID and projector build ID|Stable for one run; resume keeps manifest and checkpoint|Manifest evidence catalog checkpoints and target metadata|Replay headers structured logs and cutover record|Operations owner and source/target manifests validate|No customer PII; permissions separate from live publisher; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
IDENTITY|trace|Instrumentation creates distributed diagnostic trace ID|Usually stable within sampled causal request; not guaranteed across offline replay|Trace backend for sampled retention only|W3C Trace Context; linked from logs when present|Telemetry backend validates format not business truth|Sampling-sensitive; no secret token raw tenant user or account identifier; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
IDENTITY|span|Instrumentation creates operation-local child ID|New per execution attempt|Trace backend only|W3C Trace Context within sampled trace|Telemetry backend validates parentage only|Not lineage idempotency authority or audit completeness; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23

id	creator	retry_replay	persistence	propagation	validator	handling
request	API edge creates per transport attempt	New across retry and replay	Access log for diagnostic horizon only	HTTP header and structured log; never used as effect key	API edge validates syntax and clock relation only	Tokenized; not a metric dimension; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
correlation	First business entry point creates conversation ID	Stable across related workflow and explicit retry; retained on replay	Command record event envelope and evidence index	Message metadata structured logs traces and workflow input	Command or workflow authority validates membership	Opaque random value; bounded query index not metric dimension; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
causation	Producer names immediate parent command or event	Stable for the emitted child; preserved through replay	Outbox and event envelope	Message metadata and evidence store	Parent authority or durable event log validates edge	No raw payload or PII; detect missing parent; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
command	Client or command API creates logical business request ID	Stable across all client retry and recovery replay	Atomic command idempotency record with fingerprint and result	API request command record outbox and downstream lineage	Command authority validates fingerprint and one-result mapping	High-cardinality structured evidence; never unbounded metric label; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
event	Authoritative producer creates immutable event ID	Stable across delivery retry and replay; repair transform creates new ID plus lineage	Transactional outbox durable log and consumer inbox	Event envelope message metadata and manifests	Producer outbox and source authority validate identity and version	Opaque ID; aggregate duplicate rate in metrics; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
order	Order authority creates after valid acceptance	Stable for lifecycle; cancel or replace links rather than reuses semantics	Order authority and downstream facts	Payload and durable evidence; tokenized in broad logs	Order authority validates lifecycle version	Break-glass lookup maps token to raw ID under Audit owner; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
execution	Matcher or venue authority creates for each fill fact	Stable; bust or correct is a new linked fact	Execution journal venue report and posting lineage	Execution event and reconciliation evidence	Matcher journal or venue report validates	Never treat trace or portfolio update as execution identity; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
account	Account authority creates governed identifier	Stable subject to governed migration; replay preserves	Account authority reservations ledger and evidence index	Tokenized application context; raw only in restricted stores	Account authority validates tenant ownership	Raw account numbers prohibited in baggage logs and metric dimensions; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
workflow	Durable coordinator creates process instance	Stable across task retries; redrive policy records new attempt lineage	Workflow state and business process authority	Workflow metadata tasks and receipts	Coordinator plus domain authority validate process and effects	Do not infer downstream exactly once from workflow ID; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
source_version	Single authoritative writer assigns per aggregate sequence version and epoch	Stable on replay; correction appends next version	Authority journal or versioned state outbox and inbox	Event envelope checkpoint and projection manifest	Authority validates monotonic version and active writer epoch	Use bounded gap counts in metrics and full values in evidence; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
replay_build	Operator tooling creates signed replay manifest ID and projector build ID	Stable for one run; resume keeps manifest and checkpoint	Manifest evidence catalog checkpoints and target metadata	Replay headers structured logs and cutover record	Operations owner and source/target manifests validate	No customer PII; permissions separate from live publisher; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
trace	Instrumentation creates distributed diagnostic trace ID	Usually stable within sampled causal request; not guaranteed across offline replay	Trace backend for sampled retention only	W3C Trace Context; linked from logs when present	Telemetry backend validates format not business truth	Sampling-sensitive; no secret token raw tenant user or account identifier; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
span	Instrumentation creates operation-local child ID	New per execution attempt	Trace backend only	W3C Trace Context within sampled trace	Telemetry backend validates parentage only	Not lineage idempotency authority or audit completeness; Inference: local propagation policy from C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23

Inference: use error-biased or tail sampling only after confirming the collector has enough headroom; head sampling is cheaper but can discard the rare slow/error trace, while tail sampling buffers more data and can fail under load. Propagate only allow-listed, tokenized context. The Security owner owns redaction rules; Audit Operations owns two-person break-glass re-identification and records who looked up what and why. Stable business IDs go to indexed evidence/log fields, not CloudWatch or OpenTelemetry metric dimensions whose series count grows with customers, accounts, orders, or events.

Outcome-first dashboards and alarms

Model details · task11 alarms

ALARM|ALM01|Executive user outcomes and budget burn|Symptom|Budgeted service/latency bad and eligible counts for 5m 1h 6h 3d; zero-tolerance safety counters remain separate|BRN01 requires both 5m and 1h normalized burn at least 14.4; BRN02 requires both 6h and 3d burn at least 1.0; minimum eligible gates and missing-data rules apply|BRN01 pages and holds releases; BRN02 tickets and holds releases; any safety counter pages/freezes immediately outside budget|Product and service owners|Affected RBK and incident lead selected by OPMAP|Minimum eligible count; synthetic plus real traffic; exclusions graphed separately|Low-cardinality product region cohort; drill to tokenized IDs|Metric queries and paging toil; recording rules bound query cost|SLO population reconciles to authority manifest and post-incident safety proof passes; Inference: local alarm policy from C117 C119; F39 and A128 A129 A130 A131 A139 A140 A141 A142 retrieved 2026-08-23
ALARM|ALM02|Authority and correctness controls|Symptom|Unresolved accepted commands duplicate effects version gaps writer-epoch conflicts exact-unit imbalance provider and audit gaps; immediate|Evaluate every zero-tolerance event without averaging|Page and freeze affected authority scope|Domain ledger reconciliation and security owners|RBK01 RBK02 RBK05 RBK06 RBK07 RBK08|Require durable manifest or authority query; deduplicate one incident without muting new scopes|Aggregate metric by product currency and severity; full IDs in evidence store|Unsampled evidence storage and reconciliation compute are protected cost|Independent manifest control totals one writer and break lifecycle VERIFIED then CLOSED; Inference: local alarm policy from C117 C119; F39 and A128 A129 A130 A131 A139 A140 A141 A142 retrieved 2026-08-23
ALARM|ALM03|Transport backlog and dependency saturation|Cause|Oldest age arrival and commit rate net drain throttles queue or shard lag dependency latency and fairness by bounded cohort; 1m 5m 15m|Evaluate proximity to SLO and retention with positive-drain branch|Page only when runbook can contain imminent harm; otherwise ticket or dashboard|Messaging consumer and dependency owners|RBK03 RBK04|Age and net drain not depth alone; maintenance and replay annotations; per-key probes|Bounded tenant tier priority shard partitions; never raw IDs|Detailed metrics logs replay and spare capacity; cap optional dimensions first|Backlog drains with positive spare no starvation and admitted-work manifest reconciles; Inference: local alarm policy from C117 C119; F39 and A128 A129 A130 A131 A139 A140 A141 A142 retrieved 2026-08-23
ALARM|ALM04|Per-service diagnosis|Cause|API Gateway Lambda EventBridge SQS SNS Kinesis DynamoDB Streams Steps Firehose Flink MSK matcher documented metrics; 1m and service-fit windows|Evaluate with correct statistic dimensions and missing-data policy|Dashboard by default; page only if immediate component action protects a symptom|Platform and component owner|OPMAP-selected RBK|Correct namespace dimensions statistic missing-data policy and deployment annotations|Approved dimensions only; exemplars point to traces or logs|Detailed dimensions and high log volume are explicit Task 10 drivers|Component recovers and corresponding business symptom plus correctness proof clears; Inference: local alarm policy from C117 C119; F39 and A128 A129 A130 A131 A139 A140 A141 A142 retrieved 2026-08-23
ALARM|ALM05|Deployment replay and DR state|Symptom and cause|Canary cohort SLO safety counters schema rejects replay build lag active writer epoch stale-route probes RTO clock RPO age; continuous during change|Evaluate canary against old cohort and fixed safety stop|Automatically stop safety break; page failed stop fence or recovery gate|Release owner incident commander domain approver|REL route plus RBK05 or RBK08|Compare old and new cohorts; minimum volume; synthetic compatibility and stale-client probes|Build deployment epoch and Region are bounded dimensions|Parallel versions replay reserve and retained evidence increase temporary cost|Retained rollback target remains safe; manifests match; one writer; measured objectives recorded; Inference: local alarm policy from C117 C119; F39 and A128 A129 A130 A131 A139 A140 A141 A142 retrieved 2026-08-23

id	layer	symptom_cause	query_window	evaluation	action	owner	route	guard	cardinality	cost	closure
ALM01	Executive user outcomes and budget burn	Symptom	Budgeted service/latency bad and eligible counts for 5m 1h 6h 3d; zero-tolerance safety counters remain separate	BRN01 requires both 5m and 1h normalized burn at least 14.4; BRN02 requires both 6h and 3d burn at least 1.0; minimum eligible gates and missing-data rules apply	BRN01 pages and holds releases; BRN02 tickets and holds releases; any safety counter pages/freezes immediately outside budget	Product and service owners	Affected RBK and incident lead selected by OPMAP	Minimum eligible count; synthetic plus real traffic; exclusions graphed separately	Low-cardinality product region cohort; drill to tokenized IDs	Metric queries and paging toil; recording rules bound query cost	SLO population reconciles to authority manifest and post-incident safety proof passes; Inference: local alarm policy from C117 C119; F39 and A128 A129 A130 A131 A139 A140 A141 A142 retrieved 2026-08-23
ALM02	Authority and correctness controls	Symptom	Unresolved accepted commands duplicate effects version gaps writer-epoch conflicts exact-unit imbalance provider and audit gaps; immediate	Evaluate every zero-tolerance event without averaging	Page and freeze affected authority scope	Domain ledger reconciliation and security owners	RBK01 RBK02 RBK05 RBK06 RBK07 RBK08	Require durable manifest or authority query; deduplicate one incident without muting new scopes	Aggregate metric by product currency and severity; full IDs in evidence store	Unsampled evidence storage and reconciliation compute are protected cost	Independent manifest control totals one writer and break lifecycle VERIFIED then CLOSED; Inference: local alarm policy from C117 C119; F39 and A128 A129 A130 A131 A139 A140 A141 A142 retrieved 2026-08-23
ALM03	Transport backlog and dependency saturation	Cause	Oldest age arrival and commit rate net drain throttles queue or shard lag dependency latency and fairness by bounded cohort; 1m 5m 15m	Evaluate proximity to SLO and retention with positive-drain branch	Page only when runbook can contain imminent harm; otherwise ticket or dashboard	Messaging consumer and dependency owners	RBK03 RBK04	Age and net drain not depth alone; maintenance and replay annotations; per-key probes	Bounded tenant tier priority shard partitions; never raw IDs	Detailed metrics logs replay and spare capacity; cap optional dimensions first	Backlog drains with positive spare no starvation and admitted-work manifest reconciles; Inference: local alarm policy from C117 C119; F39 and A128 A129 A130 A131 A139 A140 A141 A142 retrieved 2026-08-23
ALM04	Per-service diagnosis	Cause	API Gateway Lambda EventBridge SQS SNS Kinesis DynamoDB Streams Steps Firehose Flink MSK matcher documented metrics; 1m and service-fit windows	Evaluate with correct statistic dimensions and missing-data policy	Dashboard by default; page only if immediate component action protects a symptom	Platform and component owner	OPMAP-selected RBK	Correct namespace dimensions statistic missing-data policy and deployment annotations	Approved dimensions only; exemplars point to traces or logs	Detailed dimensions and high log volume are explicit Task 10 drivers	Component recovers and corresponding business symptom plus correctness proof clears; Inference: local alarm policy from C117 C119; F39 and A128 A129 A130 A131 A139 A140 A141 A142 retrieved 2026-08-23
ALM05	Deployment replay and DR state	Symptom and cause	Canary cohort SLO safety counters schema rejects replay build lag active writer epoch stale-route probes RTO clock RPO age; continuous during change	Evaluate canary against old cohort and fixed safety stop	Automatically stop safety break; page failed stop fence or recovery gate	Release owner incident commander domain approver	REL route plus RBK05 or RBK08	Compare old and new cohorts; minimum volume; synthetic compatibility and stale-client probes	Build deployment epoch and Region are bounded dimensions	Parallel versions replay reserve and retained evidence increase temporary cost	Retained rollback target remains safe; manifests match; one writer; measured objectives recorded; Inference: local alarm policy from C117 C119; F39 and A128 A129 A130 A131 A139 A140 A141 A142 retrieved 2026-08-23

The dashboard order is deliberate: current customer/business outcomes and burn; authority/correctness interrupts; transport and dependency saturation; per-service causes; then deployment, replay, and DR state. An operator starts at the affected outcome, finds the owning FSR, and follows the mapped runbook. Averages are supplemented with tails, oldest age, cohort gaps, and exact-unit totals. A green component never closes the incident by itself.

Audit evidence versus diagnostic telemetry

Tracing helps explain a sampled attempt, but the durable business lineage must survive even when that trace was never retained. The evidence catalog below separates records needed to prove an assertion from logs and metrics used to investigate it. For each class, name the producing population, retention/access owner, and a completeness test; encryption or integrity checks alone do not supply missing records.

Model details · task11 evidence

EVIDENCE|EVD01|Authoritative business records and append-oriented postings|Decide accepted commands executions obligations settlements and balanced postings|Complete only for named authority and transaction or journal scope|Command execution obligation settlement and ledger authorities|Stable business IDs versions epochs exact decimal or integer-minor units and correction lineage|Tokenize customer/account identifiers in broad access; raw restricted by purpose|Business Legal and Compliance owners set product jurisdiction and hold schedule|Conditional or append control KMS access separation immutable correction lineage and dual control|Authority APIs ledger queries and signed export manifests|Never sampled|Legal hold suspends governed deletion; corrections append rather than erase|Writes indexes backups cross-Region storage KMS and controlled query capacity|Reconcile identities versions exact totals and adjacent windows; Inference: local evidence policy from C109 C117 C118 C122; F14 F15 F27 retrieved 2026-08-22; F39 F40 F41 and A135 retrieved 2026-08-23
EVIDENCE|EVD02|Integrity-validated audit evidence and access history|Prove a named application access configuration or change assertion|Complete only for declared application producers CloudTrail selectors accounts Regions event types and manifest|Application audit producer CloudTrail trail or event store and evidence catalog|Actor action target request or business token policy version time and artifact digest|No secret or raw PII in broad logs; break-glass mapping separately audited|Audit Legal and Security owners approve retention deletion and holds|Digest chain or signed manifest CloudTrail validation Object Lock where selected KMS and least-privilege read|Evidence catalog then immutable store or CloudTrail Lake query by assertion|Never sampled for declared assertion population|Expiry only under approved schedule and no active hold; deletion receipt retained|Ingestion data events storage retention queries KMS replication and support|Manifest completeness selector coverage integrity check access review and retrieval drill; Inference: local evidence policy from C109 C117 C118 C122; F14 F15 F27 retrieved 2026-08-22; F39 F40 F41 and A135 retrieved 2026-08-23
EVIDENCE|EVD03|Reconciliation manifests and control totals|Detect silent loss duplicate corruption and cross-authority drift|Complete for declared UTC half-open population sources watermarks units and late-arrival policy|Independent reconciliation job plus source owners|Manifest ID source versions counts exact amounts currency instrument and break lifecycle|Tokenized record references with restricted drill-down|Reconciliation and Compliance owners retain through correction and audit horizon|Signed immutable manifest dual approval and separate write/read roles|Break console manifest store and source evidence query|Never sampled|Hold with underlying evidence; delete only after both horizons and closed breaks|Full scans exports exact aggregation storage and investigator time|Recompute original plus adjacent windows and require VERIFIED then CLOSED; Inference: local evidence policy from C109 C117 C118 C122; F14 F15 F27 retrieved 2026-08-22; F39 F40 F41 and A135 retrieved 2026-08-23
EVIDENCE|EVD04|Operational logs|Diagnose code transport dependency and policy decisions|Best effort unless a named audit assertion explicitly promotes a field to EVD02|Applications gateways runtimes and operators|Timestamp trace link deployment error class tokenized business reference and policy version|Allow-list fields redact payload headers secrets tokens and raw account/customer data|SRE and Security set short tiered retention; Legal approves any promoted audit stream|Encrypted centralized access scoped and exfiltration monitored; ordinary logs may be mutable|Log query with bounded indexes and trace exemplars|Success logs may be sampled after safety fields have durable evidence; errors retained by policy|Shorten routine debug retention first; legal hold only for promoted evidence|Ingestion volume indexing retention cross-Region transfer NAT KMS and query scans|Schema/redaction tests drop-rate monitor and incident-query drill; Inference: local evidence policy from C109 C117 C118 C122; F14 F15 F27 retrieved 2026-08-22; F39 F40 F41 and A135 retrieved 2026-08-23
EVIDENCE|EVD05|Traces and profiles|Explain causal timing retries dependency calls and code hotspots|Sampling-sensitive diagnostic view; never complete business lineage|OpenTelemetry instrumentation collectors and profiler|Trace and span IDs service operation status deployment and allow-listed tokens|No secrets tokens raw PII account numbers or unrestricted tenant/user baggage|SRE and Security set shortest useful retention and sampling|Collector and backend access scoped; baggage allow-list and export boundary reviewed|Trace backend linked from symptom exemplars|Head tail or error-biased sampling allowed; audit evidence never depends on sample|Delete on diagnostic schedule unless incident snapshot is promoted under approval|Instrumentation CPU collector memory network egress storage and query|Sampling-bias study propagation test redaction scan and known-error trace drill; Inference: local evidence policy from C109 C117 C118 C122; F14 F15 F27 retrieved 2026-08-22; F39 F40 F41 and A135 retrieved 2026-08-23
EVIDENCE|EVD06|Metrics|Detect trends symptoms causes saturation and budget consumption cheaply|Aggregated and lossy; completeness limited by emission aggregation dimensions and missing-data policy|Services applications recording rules and reconciliation exporters|Metric name unit statistic bounded dimensions and recording-rule version|No raw PII secrets tokens order account or unrestricted tenant/user dimension|SRE owns retention and dimensional allow-list with FinOps review|Workspace write/read roles alarm-change audit and bounded cross-account access|Outcome dashboards alarms and drill-down exemplars|Aggregation is intrinsic; never substitute for record evidence|Platform retention policy; no legal hold assumption unless explicitly classified|Series cardinality resolution retention cross-account transfer and alarm/query count|Unit/dimension tests missing-data canary and manifest comparison for derived safety gauges; Inference: local evidence policy from C109 C117 C118 C122; F14 F15 F27 retrieved 2026-08-22; F39 F40 F41 and A135 retrieved 2026-08-23

id	class	purpose	boundary	producer	schema_identity	redaction	retention	integrity_access	query	sampling	deletion	cost	validation
EVD01	Authoritative business records and append-oriented postings	Decide accepted commands executions obligations settlements and balanced postings	Complete only for named authority and transaction or journal scope	Command execution obligation settlement and ledger authorities	Stable business IDs versions epochs exact decimal or integer-minor units and correction lineage	Tokenize customer/account identifiers in broad access; raw restricted by purpose	Business Legal and Compliance owners set product jurisdiction and hold schedule	Conditional or append control KMS access separation immutable correction lineage and dual control	Authority APIs ledger queries and signed export manifests	Never sampled	Legal hold suspends governed deletion; corrections append rather than erase	Writes indexes backups cross-Region storage KMS and controlled query capacity	Reconcile identities versions exact totals and adjacent windows; Inference: local evidence policy from C109 C117 C118 C122; F14 F15 F27 retrieved 2026-08-22; F39 F40 F41 and A135 retrieved 2026-08-23
EVD02	Integrity-validated audit evidence and access history	Prove a named application access configuration or change assertion	Complete only for declared application producers CloudTrail selectors accounts Regions event types and manifest	Application audit producer CloudTrail trail or event store and evidence catalog	Actor action target request or business token policy version time and artifact digest	No secret or raw PII in broad logs; break-glass mapping separately audited	Audit Legal and Security owners approve retention deletion and holds	Digest chain or signed manifest CloudTrail validation Object Lock where selected KMS and least-privilege read	Evidence catalog then immutable store or CloudTrail Lake query by assertion	Never sampled for declared assertion population	Expiry only under approved schedule and no active hold; deletion receipt retained	Ingestion data events storage retention queries KMS replication and support	Manifest completeness selector coverage integrity check access review and retrieval drill; Inference: local evidence policy from C109 C117 C118 C122; F14 F15 F27 retrieved 2026-08-22; F39 F40 F41 and A135 retrieved 2026-08-23
EVD03	Reconciliation manifests and control totals	Detect silent loss duplicate corruption and cross-authority drift	Complete for declared UTC half-open population sources watermarks units and late-arrival policy	Independent reconciliation job plus source owners	Manifest ID source versions counts exact amounts currency instrument and break lifecycle	Tokenized record references with restricted drill-down	Reconciliation and Compliance owners retain through correction and audit horizon	Signed immutable manifest dual approval and separate write/read roles	Break console manifest store and source evidence query	Never sampled	Hold with underlying evidence; delete only after both horizons and closed breaks	Full scans exports exact aggregation storage and investigator time	Recompute original plus adjacent windows and require VERIFIED then CLOSED; Inference: local evidence policy from C109 C117 C118 C122; F14 F15 F27 retrieved 2026-08-22; F39 F40 F41 and A135 retrieved 2026-08-23
EVD04	Operational logs	Diagnose code transport dependency and policy decisions	Best effort unless a named audit assertion explicitly promotes a field to EVD02	Applications gateways runtimes and operators	Timestamp trace link deployment error class tokenized business reference and policy version	Allow-list fields redact payload headers secrets tokens and raw account/customer data	SRE and Security set short tiered retention; Legal approves any promoted audit stream	Encrypted centralized access scoped and exfiltration monitored; ordinary logs may be mutable	Log query with bounded indexes and trace exemplars	Success logs may be sampled after safety fields have durable evidence; errors retained by policy	Shorten routine debug retention first; legal hold only for promoted evidence	Ingestion volume indexing retention cross-Region transfer NAT KMS and query scans	Schema/redaction tests drop-rate monitor and incident-query drill; Inference: local evidence policy from C109 C117 C118 C122; F14 F15 F27 retrieved 2026-08-22; F39 F40 F41 and A135 retrieved 2026-08-23
EVD05	Traces and profiles	Explain causal timing retries dependency calls and code hotspots	Sampling-sensitive diagnostic view; never complete business lineage	OpenTelemetry instrumentation collectors and profiler	Trace and span IDs service operation status deployment and allow-listed tokens	No secrets tokens raw PII account numbers or unrestricted tenant/user baggage	SRE and Security set shortest useful retention and sampling	Collector and backend access scoped; baggage allow-list and export boundary reviewed	Trace backend linked from symptom exemplars	Head tail or error-biased sampling allowed; audit evidence never depends on sample	Delete on diagnostic schedule unless incident snapshot is promoted under approval	Instrumentation CPU collector memory network egress storage and query	Sampling-bias study propagation test redaction scan and known-error trace drill; Inference: local evidence policy from C109 C117 C118 C122; F14 F15 F27 retrieved 2026-08-22; F39 F40 F41 and A135 retrieved 2026-08-23
EVD06	Metrics	Detect trends symptoms causes saturation and budget consumption cheaply	Aggregated and lossy; completeness limited by emission aggregation dimensions and missing-data policy	Services applications recording rules and reconciliation exporters	Metric name unit statistic bounded dimensions and recording-rule version	No raw PII secrets tokens order account or unrestricted tenant/user dimension	SRE owns retention and dimensional allow-list with FinOps review	Workspace write/read roles alarm-change audit and bounded cross-account access	Outcome dashboards alarms and drill-down exemplars	Aggregation is intrinsic; never substitute for record evidence	Platform retention policy; no legal hold assumption unless explicitly classified	Series cardinality resolution retention cross-account transfer and alarm/query count	Unit/dimension tests missing-data canary and manifest comparison for derived safety gauges; Inference: local evidence policy from C109 C117 C118 C122; F14 F15 F27 retrieved 2026-08-22; F39 F40 F41 and A135 retrieved 2026-08-23

CloudTrail has management, data, network-activity, and Insights event scopes; trails and event data stores default to management events rather than every scope (C122, A135 retrieved 2026-08-23). CloudTrail integrity validation, Object Lock, encryption, and KMS protect named artifacts inside configured boundaries. They do not prove application-event completeness, semantic correctness, suitable retention, or compliance (C109, A41 and A122 retrieved 2026-08-22).

Portable cost controls use ratios, not fresh price guesses:

• telemetry_bytes_per_business_event = ingested_log_trace_metric_bytes / eligible_business_events;
• retained_evidence_bytes_per_authoritative_fact = compressed_retained_bytes / authoritative_facts;
• series_per_bounded_cohort = active_series / approved_product_region_tier_cohorts;
• reconciliation_compute_per_closed_window = compute_and_query_units / clean_or_owned_break_windows;
• operational_burden_per_release = engineer_hours + on_call_interrupt_hours + exercise_hours.

Protect EVD01–EVD03 first. When cost or saturation requires reduction, remove debug payloads, routine-success log sampling, trace sample rate/retention, profile duration, and optional metric dimensions in that order, subject to incident needs. Never remove financial authority, accepted-command lineage, exact reconciliation, required audit population, or legal-hold evidence. Task 10's other drivers—KMS, cross-Region storage/transfer, NAT path, replay reads/compute/writes, backups, support, and people/on-call burden—remain explicit rather than hidden in one storage number.

Security boundary and incident contract

AWS Well-Architected frames security around protecting data and systems, controlling access, and responding to security events; this chapter turns that high-level scope into named fintech authority, evidence, containment, and reconciliation contracts (C120, A138 retrieved 2026-08-23).

Model details · task11 security

SECURITY|SEC01|Stolen or long-lived human or workload credential changes authority or evidence|Production command ledger deployment and evidence access|Federated human access with MFA and temporary role sessions; workload roles with no embedded key; permission boundary and reviewed session duration|Identity provider CloudTrail and application audit show principal session policy version action and anomaly|Separate prod nonprod security and evidence roles; scoped account and resource permissions|Disable identity revoke sessions or role trust and freeze affected changes|Inventory actions since earliest exposure rotate dependent credentials reconcile authority and independently approve restore|Security IAM and affected domain owners|Session already issued caching and third-party credentials can extend exposure|Inference: C120; A38 retrieved 2026-08-22; A132 A138 retrieved 2026-08-23
SECURITY|SEC02|Cross-tenant or cross-account request reads or mutates another customer's records|Tenant-scoped command account reservations ledger projection and evidence|Authenticate issuer audience and expiry; derive tenant context server-side; enforce tenant/account predicates and tenant-scoped credentials or silo resource policy; negative authorization tests|Denied and allowed access audit with tokenized tenant principal resource and policy version plus cross-tenant canary|Pool resources use explicit runtime isolation; silo account/resource reduces blast but shares control plane|Revoke tenant session and scoped role quarantine affected partitions deny cross-account route|Determine accessed identities from audit and application evidence correct unauthorized effects notify/escalate by policy and re-run cross-tenant tests|Tenant platform Security and domain data owner|Bugs in shared code indexes exports caches or support tooling remain cross-tenant paths|Inference: C120 C122; A136 retrieved 2026-08-23
SECURITY|SEC03|Overbroad identity or resource policy enables service confused deputy or unauthorized event destination|Event buses queues topics keys functions and cross-account destinations|Reason over action resource principal condition and data scope; validate policy; constrain service principal with SourceArn SourceAccount or organization condition and explicit destination policy|IAM Access Analyzer findings CloudTrail policy changes denied access and synthetic cross-account publish|Per rule topic queue key function and account; separate publisher and consumer roles|Detach or explicit-deny policy disable rule revoke trust and retain failed-event evidence|Compare attempted and delivered manifests repair only missing authorized events and investigate unauthorized delivery|Cloud platform and Messaging owner|Wildcard-free statements can still cover wrong resources conditions actions or data|Inference: C120; A132 A143 retrieved 2026-08-23
SECURITY|SEC04|KMS policy grant or key outage exposes data or halts command audit and recovery paths|Ciphertext keys ledger evidence backups secrets and availability of protected authorities|Key policy is primary boundary; scoped grants and encryption context conditions; separate key admins and users; tested dependency/failure mode|CloudTrail KMS calls grant and policy changes decrypt denials key state and application inability signal|Keys separated by environment purpose and regulated data class with documented shared dependency|Disable compromised grant or principal; do not delete key; fail closed for authority write when evidence cannot be protected|Restore authorized key path from controlled config rotate or re-encrypt where required and reconcile all writes during outage|KMS Security platform and data owner|Encryption context is plaintext in CloudTrail and key unavailability can become shared blast radius|Inference: C121; A133 retrieved 2026-08-23
SECURITY|SEC05|Secret compromise stale consumer or failed rotation enables unauthorized provider or database access|Database provider webhook API and signing credentials|Secrets Manager storage scoped retrieval scheduled rotation appropriate strategy no secret in code/log and consumer refresh test|Rotation events secret access anomalous provider action authentication failures and old-version use|Secret per environment purpose and provider account; restrict rotation deputy to target|Revoke provider credential disable principal rotate immediately freeze ambiguous external effects|Verify new credential end-to-end retire old version inspect exposure window and reconcile provider receipts with intents and ledger|Security secret owner and external operations|Rotation has a transition window and external provider revocation may lag|Inference: C121; A134 retrieved 2026-08-23
SECURITY|SEC06|Public API abuse injection bot burst or network pivot exhausts or bypasses business controls|API availability command admission and private administrative surfaces|Authentication and authorization at application edge; schema and size limits; rate and concurrency policy; WAF for supported traffic patterns; private endpoints only for justified trust path|WAF and gateway requests auth denies admission rejects dependency saturation and business SLI by bounded cohort|Public data plane separated from admin and evidence planes; network segmentation limits path not identity|Block abusive principal or pattern cap admission isolate admin path and preserve legitimate priority lanes|Validate no accepted-command loss inspect rejected cohort rotate exposed route and tune rule through canary|API Security and SRE owners|WAF does not authenticate; rate limits can harm shared NAT clients; private connectivity can carry authorized or compromised abuse|Inference: C120 C122; A42 retrieved 2026-08-22; A128 A144 retrieved 2026-08-23
SECURITY|SEC07|PII secret token or account identifier leaks through logs baggage metrics audit query or support access|Customer identity financial data credentials and regulated evidence|Classify fields at schema; tokenize and redact before export; baggage and dimension allow-list; purpose-scoped evidence access and two-person break-glass|DLP/redaction tests export scans access audit break-glass reason and unusual query alerts|Separate token vault restricted evidence broad telemetry and support view|Stop export revoke reader preserve incident evidence and rotate exposed secret or token mapping|Scope recipients and retained copies delete only when legally permitted notify per policy and prove redaction before resume|Data Protection Security Audit and Legal owners|Derived combinations can re-identify and third-party telemetry retention may persist|Inference: C118 C122; F41; A135 retrieved 2026-08-23
SECURITY|SEC08|CloudTrail selector Region account or delivery gap creates false audit confidence|Control-plane and selected data/network activity evidence|Organization trail or event store design with explicit accounts Regions event types selectors validation destination protection and delivery alarm plus application audit|Configuration change selector coverage delivery errors digest validation catalog completeness and access query|Named CloudTrail scope separated from application financial audit population|Freeze high-risk changes repair selector/delivery protect available logs and open evidence break|Backfill only where source exists correlate application/change evidence classify unrecoverable gap and obtain independent closure|Audit platform Security Compliance and service owner|Events not selected or produced cannot be recovered; order is not a stack trace|Inference: C109 C122; A41 retrieved 2026-08-22; A135 retrieved 2026-08-23
SECURITY|SEC09|Unauthorized or tampered deployment operator action or artifact changes execution semantics|Source build artifact infrastructure schema release authority and rollback target|Protected branch reviewed commit signed/provenance-checked immutable artifact least-privilege deploy role two-person high-risk approval and policy-as-code gate|Commit build digest deploy principal change set canary safety signals policy finding and evidence manifest|Separate build deploy approval and runtime roles plus environment accounts|Stop rollout revoke deploy session freeze artifact and traffic alias preserve old and new evidence|Restore retained known-good target only if compatible; otherwise roll forward and reconcile already-emitted facts|Release Engineering Security and domain approver|A valid artifact can contain a semantic defect and rollback cannot undo external facts|Inference: C120 C123; A132 A137 retrieved 2026-08-23

id	threat	protected	prevention	detection	blast	containment	recovery	owner	residual	governance
SEC01	Stolen or long-lived human or workload credential changes authority or evidence	Production command ledger deployment and evidence access	Federated human access with MFA and temporary role sessions; workload roles with no embedded key; permission boundary and reviewed session duration	Identity provider CloudTrail and application audit show principal session policy version action and anomaly	Separate prod nonprod security and evidence roles; scoped account and resource permissions	Disable identity revoke sessions or role trust and freeze affected changes	Inventory actions since earliest exposure rotate dependent credentials reconcile authority and independently approve restore	Security IAM and affected domain owners	Session already issued caching and third-party credentials can extend exposure	Inference: C120; A38 retrieved 2026-08-22; A132 A138 retrieved 2026-08-23
SEC02	Cross-tenant or cross-account request reads or mutates another customer's records	Tenant-scoped command account reservations ledger projection and evidence	Authenticate issuer audience and expiry; derive tenant context server-side; enforce tenant/account predicates and tenant-scoped credentials or silo resource policy; negative authorization tests	Denied and allowed access audit with tokenized tenant principal resource and policy version plus cross-tenant canary	Pool resources use explicit runtime isolation; silo account/resource reduces blast but shares control plane	Revoke tenant session and scoped role quarantine affected partitions deny cross-account route	Determine accessed identities from audit and application evidence correct unauthorized effects notify/escalate by policy and re-run cross-tenant tests	Tenant platform Security and domain data owner	Bugs in shared code indexes exports caches or support tooling remain cross-tenant paths	Inference: C120 C122; A136 retrieved 2026-08-23
SEC03	Overbroad identity or resource policy enables service confused deputy or unauthorized event destination	Event buses queues topics keys functions and cross-account destinations	Reason over action resource principal condition and data scope; validate policy; constrain service principal with SourceArn SourceAccount or organization condition and explicit destination policy	IAM Access Analyzer findings CloudTrail policy changes denied access and synthetic cross-account publish	Per rule topic queue key function and account; separate publisher and consumer roles	Detach or explicit-deny policy disable rule revoke trust and retain failed-event evidence	Compare attempted and delivered manifests repair only missing authorized events and investigate unauthorized delivery	Cloud platform and Messaging owner	Wildcard-free statements can still cover wrong resources conditions actions or data	Inference: C120; A132 A143 retrieved 2026-08-23
SEC04	KMS policy grant or key outage exposes data or halts command audit and recovery paths	Ciphertext keys ledger evidence backups secrets and availability of protected authorities	Key policy is primary boundary; scoped grants and encryption context conditions; separate key admins and users; tested dependency/failure mode	CloudTrail KMS calls grant and policy changes decrypt denials key state and application inability signal	Keys separated by environment purpose and regulated data class with documented shared dependency	Disable compromised grant or principal; do not delete key; fail closed for authority write when evidence cannot be protected	Restore authorized key path from controlled config rotate or re-encrypt where required and reconcile all writes during outage	KMS Security platform and data owner	Encryption context is plaintext in CloudTrail and key unavailability can become shared blast radius	Inference: C121; A133 retrieved 2026-08-23
SEC05	Secret compromise stale consumer or failed rotation enables unauthorized provider or database access	Database provider webhook API and signing credentials	Secrets Manager storage scoped retrieval scheduled rotation appropriate strategy no secret in code/log and consumer refresh test	Rotation events secret access anomalous provider action authentication failures and old-version use	Secret per environment purpose and provider account; restrict rotation deputy to target	Revoke provider credential disable principal rotate immediately freeze ambiguous external effects	Verify new credential end-to-end retire old version inspect exposure window and reconcile provider receipts with intents and ledger	Security secret owner and external operations	Rotation has a transition window and external provider revocation may lag	Inference: C121; A134 retrieved 2026-08-23
SEC06	Public API abuse injection bot burst or network pivot exhausts or bypasses business controls	API availability command admission and private administrative surfaces	Authentication and authorization at application edge; schema and size limits; rate and concurrency policy; WAF for supported traffic patterns; private endpoints only for justified trust path	WAF and gateway requests auth denies admission rejects dependency saturation and business SLI by bounded cohort	Public data plane separated from admin and evidence planes; network segmentation limits path not identity	Block abusive principal or pattern cap admission isolate admin path and preserve legitimate priority lanes	Validate no accepted-command loss inspect rejected cohort rotate exposed route and tune rule through canary	API Security and SRE owners	WAF does not authenticate; rate limits can harm shared NAT clients; private connectivity can carry authorized or compromised abuse	Inference: C120 C122; A42 retrieved 2026-08-22; A128 A144 retrieved 2026-08-23
SEC07	PII secret token or account identifier leaks through logs baggage metrics audit query or support access	Customer identity financial data credentials and regulated evidence	Classify fields at schema; tokenize and redact before export; baggage and dimension allow-list; purpose-scoped evidence access and two-person break-glass	DLP/redaction tests export scans access audit break-glass reason and unusual query alerts	Separate token vault restricted evidence broad telemetry and support view	Stop export revoke reader preserve incident evidence and rotate exposed secret or token mapping	Scope recipients and retained copies delete only when legally permitted notify per policy and prove redaction before resume	Data Protection Security Audit and Legal owners	Derived combinations can re-identify and third-party telemetry retention may persist	Inference: C118 C122; F41; A135 retrieved 2026-08-23
SEC08	CloudTrail selector Region account or delivery gap creates false audit confidence	Control-plane and selected data/network activity evidence	Organization trail or event store design with explicit accounts Regions event types selectors validation destination protection and delivery alarm plus application audit	Configuration change selector coverage delivery errors digest validation catalog completeness and access query	Named CloudTrail scope separated from application financial audit population	Freeze high-risk changes repair selector/delivery protect available logs and open evidence break	Backfill only where source exists correlate application/change evidence classify unrecoverable gap and obtain independent closure	Audit platform Security Compliance and service owner	Events not selected or produced cannot be recovered; order is not a stack trace	Inference: C109 C122; A41 retrieved 2026-08-22; A135 retrieved 2026-08-23
SEC09	Unauthorized or tampered deployment operator action or artifact changes execution semantics	Source build artifact infrastructure schema release authority and rollback target	Protected branch reviewed commit signed/provenance-checked immutable artifact least-privilege deploy role two-person high-risk approval and policy-as-code gate	Commit build digest deploy principal change set canary safety signals policy finding and evidence manifest	Separate build deploy approval and runtime roles plus environment accounts	Stop rollout revoke deploy session freeze artifact and traffic alias preserve old and new evidence	Restore retained known-good target only if compatible; otherwise roll forward and reconcile already-emitted facts	Release Engineering Security and domain approver	A valid artifact can contain a semantic defect and rollback cannot undo external facts	Inference: C120 C123; A132 A137 retrieved 2026-08-23

Concrete least-privilege reasoning from the case study

CS08 observes EventBridge targets with SQS DLQ ARNs but no matching queue resource policy. The repair is not “allow sqs:SendMessage without wildcards.” The queue policy principal must be events.amazonaws.com, action sqs:SendMessage, resource the exact DLQ ARN, and condition aws:SourceArn the exact rule ARN; the rule/deployment role separately needs only configuration actions it performs. Validate both allowed rule delivery and denied unrelated rule/account delivery, then alarm failure-to-send-to-DLQ. This proves the named path, not global least privilege (C57 from the reviewed case, C120; EventBridge DLQ policy A81 retrieved 2026-08-22; IAM confused-deputy A143 retrieved 2026-08-23).

Every security incident creates a signed evidence manifest, earliest-known exposure time, protected-resource scope, revocation actions, ambiguous business effects, reconciliation owner, notification/legal decision, and resume gate. Containment is allowed to reduce availability; it is not allowed to invent a failed outcome for an ambiguous order, payment, fill, or posting.

Deployment and schema safety

The access controls above limit who may change a system; the release contracts limit what a permitted change may do. REL labels a release procedure and EX an exercise that tests it. A traffic rollback can restore old code, but it cannot erase a newly emitted financial fact or make an old reader understand a new schema. Follow compatibility, stop conditions, retained evidence, and reconciliation together.

Model details · task11 release

RELEASE|REL01|Lambda version alias and canary|Request backward compatible; event consumer reads current and previous supported envelopes|Published immutable versions same role and DLQ constraints understood retained old version idempotent effects canary cohort and alarms|Publish then alias small cohort then staged increase; never use mutable LATEST|Business SLO safety counters authority manifests errors duration throttles and cohort comparison|Any safety break manifest gap schema reject or sustained fast burn|Rollback traffic for code-only compatible fault; roll forward if facts or schema already changed|Original identities and inbox state survive retry; replay only after fixed consumer canary|Previous published version config policy and artifact digest|Canary cohort manifests equal authority and no duplicate or missing effects; Inference: local release gate from C123; A137 retrieved 2026-08-23; F01 F25 F26 retrieved 2026-08-22
RELEASE|REL02|Producer consumer event compatibility and upcasters|Additive producer remains readable by old consumer; semantic change uses new version and explicit upcaster|Contract examples schema and semantic tests consumer inventory unknown-field behavior and retention horizon|Deploy tolerant consumers and upcasters before producer; retire old only after retained-event horizon|Old and new consumer decode same fixtures and canary events preserve identity units ordering and meaning|Any supported consumer rejects or silently changes semantic result|Rollback producer before new facts when safe; otherwise roll forward adapter and preserve original payload|Replay original event through version-selected decoder; transform creates lineage not silent edit|Old producer consumer schemas fixtures and decoder artifacts|Per-version counts identities source versions and exact business results reconcile; Inference: local release gate from C123; A137 retrieved 2026-08-23; F01 F25 F26 retrieved 2026-08-22
RELEASE|REL03|Authoritative schema or data migration|Expand then migrate then contract; every writer/read version has declared compatibility|Backup or immutable source manifest conditional version ownership exact-unit transform dry run and dual approval|Add fields/indexes then dual-read if needed backfill bounded cohorts switch authority conditionally then remove old later|Old versus new authority queries exact counts amounts versions and write-path shadow decisions|Any ambiguity duplicate authority writer mismatch or irreconcilable item|Roll back reads while old authority valid; roll forward append correction when writes changed semantics|Checkpointed idempotent migration with source versions and no external side effects|Old schema data snapshot migration manifest and compatible reader|Source and target identities versions exact totals and adjacent writes reconcile; Inference: local release gate from C123; A137 retrieved 2026-08-23; F01 F25 F26 retrieved 2026-08-22
RELEASE|REL04|Dual-read or dual-write transition|Reads may compare; writes remain single authoritative commit unless transaction closes both|Named authority divergence detector idempotency version policy repair owner and finite migration window|Prefer single write plus CDC or outbox; if dual write unavoidable record intent and independent repair before read cutover|Write success matrix source target lag exact totals and forced partial-failure tests|Any unexplained divergence or client can observe conflicting authority|Rollback read selection; do not claim dual-write rollback erased committed side|Repair from authority under manifest; replay secondary effect only with original identity|Authoritative old path divergence evidence and repair tooling|Every authoritative write maps to secondary result or owned break before cutover; Inference: local release gate from C123; A137 retrieved 2026-08-23; F01 F25 F26 retrieved 2026-08-22
RELEASE|REL05|Versioned projection rebuild vNext and conditional cutover|New projection can change read schema while authority and old view remain|Durable source full manifest isolated target build ID catch-up stream side effects suppressed exact comparison and alias condition|Backfill vNext then catch up to target watermark validate cohorts and switch alias atomically|Counts quantities exact values versions gap count freshness and representative query parity|Gap wrong value build ID mismatch unsafe side effect or live SLO pressure|Switch alias to retained old projection if still compatible; otherwise roll forward repair|Resume from signed checkpoint and original source; never rebuild in place|Old projection alias manifests source snapshot and vNext checkpoint|No gaps; exact totals and watermark match authority before and after cutover; Inference: local release gate from C123; A137 retrieved 2026-08-23; F01 F25 F26 retrieved 2026-08-22
RELEASE|REL06|Replay-safe consumer with external side effects suppressed|Consumer must distinguish live from replay without changing business identity|Replay manifest scoped role isolated destination dry run idempotent inbox side-effect mode and external receipt lookup|Deploy decoder and pure state path then dry run then one-key or one-percent canary then bounded replay|Inbox result target version attempted versus applied duplicates and zero unauthorized external calls|Any external call duplicate effect gap or live-lane SLO burn|Stop replay preserve checkpoint restore prior consumer and reconcile canary effects|Resume original identities after fix at measured spare capacity|Prior consumer replay manifest raw source and checkpoint|Source IDs equal applied or explicit quarantined IDs and external receipt count unchanged; Inference: local release gate from C123; A137 retrieved 2026-08-23; F01 F25 F26 retrieved 2026-08-22
RELEASE|REL07|Long-lived matcher journal release and writer fencing|New binary reads old journal and snapshots; write format evolves only after all rollback readers support it|Deterministic replay test shadow decision comparison one active epoch warm standby and journal backup|Deploy standby replay shadow compare fence old writer promote canary symbol cohorts then expand|Decision latency journal flush depth execution sequence exact decision digest and epoch conflicts|Any decision divergence second writer journal gap or tail objective breach|Fence new and reactivate retained old only if it reads all emitted formats; otherwise forward repair|Replay journal deterministically from snapshot with publication suppressed until checkpoint proof|Old binary journal reader snapshot writer epoch and deployment artifact|One writer identical decisions for fixture and shadow cohorts journal plus executions reconcile; Inference: local release gate from C123; A137 retrieved 2026-08-23; F01 F25 F26 retrieved 2026-08-22
RELEASE|REL08|DR configuration or routing change|Both Regions and stale clients preserve retry identity and reject fenced writer|Pre-provisioned data-plane control IaC diff dependency and KMS readiness Route 53 or ARC probes DNS TTL keepalive test RTO RPO manifest|Change non-authority dependency first canary reads fence writer test stale endpoint then route canary writes|Business probes active epoch stale-client responses replication lag recovery-point age and control totals|Second writer missing evidence breached RPO unsafe stale route or correctness gap|Return to last fenced routing only when single writer remains; failback is separate approved release|Replay missing outbox rebuild projections and reconcile externals under capacity cap|Last known routing config writer epoch authority manifests backups and Region artifacts|One active epoch measured RTO and RPO stale-route probes and financial control totals pass; Inference: local release gate from C123; A137 retrieved 2026-08-23; F01 F25 F26 retrieved 2026-08-22

id	change	compatibility	prerequisites	order	canary	stop	decision	replay	retained	proof
REL01	Lambda version alias and canary	Request backward compatible; event consumer reads current and previous supported envelopes	Published immutable versions same role and DLQ constraints understood retained old version idempotent effects canary cohort and alarms	Publish then alias small cohort then staged increase; never use mutable LATEST	Business SLO safety counters authority manifests errors duration throttles and cohort comparison	Any safety break manifest gap schema reject or sustained fast burn	Rollback traffic for code-only compatible fault; roll forward if facts or schema already changed	Original identities and inbox state survive retry; replay only after fixed consumer canary	Previous published version config policy and artifact digest	Canary cohort manifests equal authority and no duplicate or missing effects; Inference: local release gate from C123; A137 retrieved 2026-08-23; F01 F25 F26 retrieved 2026-08-22
REL02	Producer consumer event compatibility and upcasters	Additive producer remains readable by old consumer; semantic change uses new version and explicit upcaster	Contract examples schema and semantic tests consumer inventory unknown-field behavior and retention horizon	Deploy tolerant consumers and upcasters before producer; retire old only after retained-event horizon	Old and new consumer decode same fixtures and canary events preserve identity units ordering and meaning	Any supported consumer rejects or silently changes semantic result	Rollback producer before new facts when safe; otherwise roll forward adapter and preserve original payload	Replay original event through version-selected decoder; transform creates lineage not silent edit	Old producer consumer schemas fixtures and decoder artifacts	Per-version counts identities source versions and exact business results reconcile; Inference: local release gate from C123; A137 retrieved 2026-08-23; F01 F25 F26 retrieved 2026-08-22
REL03	Authoritative schema or data migration	Expand then migrate then contract; every writer/read version has declared compatibility	Backup or immutable source manifest conditional version ownership exact-unit transform dry run and dual approval	Add fields/indexes then dual-read if needed backfill bounded cohorts switch authority conditionally then remove old later	Old versus new authority queries exact counts amounts versions and write-path shadow decisions	Any ambiguity duplicate authority writer mismatch or irreconcilable item	Roll back reads while old authority valid; roll forward append correction when writes changed semantics	Checkpointed idempotent migration with source versions and no external side effects	Old schema data snapshot migration manifest and compatible reader	Source and target identities versions exact totals and adjacent writes reconcile; Inference: local release gate from C123; A137 retrieved 2026-08-23; F01 F25 F26 retrieved 2026-08-22
REL04	Dual-read or dual-write transition	Reads may compare; writes remain single authoritative commit unless transaction closes both	Named authority divergence detector idempotency version policy repair owner and finite migration window	Prefer single write plus CDC or outbox; if dual write unavoidable record intent and independent repair before read cutover	Write success matrix source target lag exact totals and forced partial-failure tests	Any unexplained divergence or client can observe conflicting authority	Rollback read selection; do not claim dual-write rollback erased committed side	Repair from authority under manifest; replay secondary effect only with original identity	Authoritative old path divergence evidence and repair tooling	Every authoritative write maps to secondary result or owned break before cutover; Inference: local release gate from C123; A137 retrieved 2026-08-23; F01 F25 F26 retrieved 2026-08-22
REL05	Versioned projection rebuild vNext and conditional cutover	New projection can change read schema while authority and old view remain	Durable source full manifest isolated target build ID catch-up stream side effects suppressed exact comparison and alias condition	Backfill vNext then catch up to target watermark validate cohorts and switch alias atomically	Counts quantities exact values versions gap count freshness and representative query parity	Gap wrong value build ID mismatch unsafe side effect or live SLO pressure	Switch alias to retained old projection if still compatible; otherwise roll forward repair	Resume from signed checkpoint and original source; never rebuild in place	Old projection alias manifests source snapshot and vNext checkpoint	No gaps; exact totals and watermark match authority before and after cutover; Inference: local release gate from C123; A137 retrieved 2026-08-23; F01 F25 F26 retrieved 2026-08-22
REL06	Replay-safe consumer with external side effects suppressed	Consumer must distinguish live from replay without changing business identity	Replay manifest scoped role isolated destination dry run idempotent inbox side-effect mode and external receipt lookup	Deploy decoder and pure state path then dry run then one-key or one-percent canary then bounded replay	Inbox result target version attempted versus applied duplicates and zero unauthorized external calls	Any external call duplicate effect gap or live-lane SLO burn	Stop replay preserve checkpoint restore prior consumer and reconcile canary effects	Resume original identities after fix at measured spare capacity	Prior consumer replay manifest raw source and checkpoint	Source IDs equal applied or explicit quarantined IDs and external receipt count unchanged; Inference: local release gate from C123; A137 retrieved 2026-08-23; F01 F25 F26 retrieved 2026-08-22
REL07	Long-lived matcher journal release and writer fencing	New binary reads old journal and snapshots; write format evolves only after all rollback readers support it	Deterministic replay test shadow decision comparison one active epoch warm standby and journal backup	Deploy standby replay shadow compare fence old writer promote canary symbol cohorts then expand	Decision latency journal flush depth execution sequence exact decision digest and epoch conflicts	Any decision divergence second writer journal gap or tail objective breach	Fence new and reactivate retained old only if it reads all emitted formats; otherwise forward repair	Replay journal deterministically from snapshot with publication suppressed until checkpoint proof	Old binary journal reader snapshot writer epoch and deployment artifact	One writer identical decisions for fixture and shadow cohorts journal plus executions reconcile; Inference: local release gate from C123; A137 retrieved 2026-08-23; F01 F25 F26 retrieved 2026-08-22
REL08	DR configuration or routing change	Both Regions and stale clients preserve retry identity and reject fenced writer	Pre-provisioned data-plane control IaC diff dependency and KMS readiness Route 53 or ARC probes DNS TTL keepalive test RTO RPO manifest	Change non-authority dependency first canary reads fence writer test stale endpoint then route canary writes	Business probes active epoch stale-client responses replication lag recovery-point age and control totals	Second writer missing evidence breached RPO unsafe stale route or correctness gap	Return to last fenced routing only when single writer remains; failback is separate approved release	Replay missing outbox rebuild projections and reconcile externals under capacity cap	Last known routing config writer epoch authority manifests backups and Region artifacts	One active epoch measured RTO and RPO stale-route probes and financial control totals pass; Inference: local release gate from C123; A137 retrieved 2026-08-23; F01 F25 F26 retrieved 2026-08-22

Lambda aliases route only between published versions and at most two versions, with documented role/DLQ constraints; low traffic can produce variance from the configured weight. CodeDeploy provides staged Lambda deployment configurations and alarm-driven rollback mechanics (C123, A137 retrieved 2026-08-23). Boundary: neither feature proves event compatibility or undoes committed facts. CloudEvents/AsyncAPI help describe envelopes and contracts, while local semantic compatibility, upcasters, and retained replay fixtures remain design work (F25, F26, C59).

Incident and DR exercises

Treat each exercise as a testable hypothesis with a contained environment, observer, stop condition, and explicit success evidence. The source marks these exercises unexecuted; their restoration objectives remain unproven until measured. Record both elapsed recovery and the correctness checks that permit service to resume.

Every row is an unexecuted planning exercise. “Result” deliberately says unmeasured; only an actual approved game day may supply measured RTO, RPO, or SLO evidence.

Model details · task11 exercises

EXERCISE|EX01|Queue or stream backlog and retry storm|Inject bounded synthetic slow dependency in non-production or isolated game-day lane; no customer or provider effects|Capacity reserve retention margin replay off switch synthetic identities and approved abort owner|Incident commander consumer dependency domain and observer-only reconciliation roles|SLO02 or SLO03 age burn while authority stays correct|Oldest age arrival commit and retry rates net drain throttles per-key fairness and manifest gap|Age crosses exercise threshold with authority probes green|Cap retry and replay shed optional work reserve live authority lane|Abort on safety break nonpositive drain retention margin or unrelated SLO harm|Remove injection restore configuration and checkpoint|Positive measured spare live age below gate and manifest population known|All admitted synthetic IDs resolved once versions and totals reconcile|Alarm timeline config versions replay manifest checkpoint and queries|Unexecuted; record measured drain time SLO burn and inferred recovery margin not vendor promise|Any expired or unresolved item remains OPEN; Inference: unexecuted local exercise policy from C117 C120 C122 C123; F39 and A132 A135 A137 retrieved 2026-08-23|FSR04 FSR06 FSR11 RBK03 DR03 CASE04 RSP03 RSP04 INV03 INV05
EXERCISE|EX02|Poison or incompatible event|Publish signed synthetic unsupported schema into isolated key or replay sandbox|Full payload retained no external side effect ordered-lane isolation and known-good consumer retained|Schema producer consumer incident and domain observers|SLO02 gap for one synthetic key without unrelated-key starvation|Validation class receive count quarantine event source version iterator age and canary effect|One nonretryable validation or second identical failure|Quarantine exact payload isolate key and stop ordinary retry|Abort if payload escapes scope external call occurs or live age rises|Remove injection restore consumer or deploy tested compatible decoder|Offline dry run then one-key canary and source retention margin valid|Gap closes original identity retained transform lineage explicit and effects reconcile|Payload hash schema fixtures consumer versions quarantine and canary manifest|Unexecuted; record detection containment and recovery duration against SLO02|Semantically unsafe but schema-valid case remains test debt; Inference: unexecuted local exercise policy from C117 C120 C122 C123; F39 and A132 A135 A137 retrieved 2026-08-23|FSR05 RBK04 DR03 CASE05 RSP03 RSP12 INV03 INV06
EXERCISE|EX03|DynamoDB throttle hot key and conditional contention|Synthetic account or key load with bounded provisioned fault or FIS-equivalent only in approved environment|No production authority mutation exact test ledger capacity ceiling stop token and per-key bulkhead|Domain capacity database and reconciliation observers|SLO01 latency or SLO03 freshness degrades for bounded cohort|ThrottledRequests correct dimensions throttle events conditional conflicts latency consumed capacity hot-key and business age|Synthetic threshold crossed and alarm routes to FSR08|Admission control per-key bulkhead reserve authority capacity and stop projection replay|Abort on unexpected table tenant production effect or exact-total mismatch|Remove load restore configuration and verify no lingering retries|Authority capacity and positive drain restored conditional decisions deterministic|One version per accepted command no duplicate posting and exact test totals balance|Load manifest key distribution metrics dimensions cancellation reasons and config|Unexecuted; record SLO impact recovery and capacity headroom|Real skew or single-key invariant may invalidate partition plan; Inference: unexecuted local exercise policy from C117 C120 C122 C123; F39 and A132 A135 A137 retrieved 2026-08-23|FSR08 FSR11 RBK03 DR01 DR02 CASE03 RSP01 RSP10 INV01 INV05
EXERCISE|EX04|Broken or stale projection and vNext rebuild|Corrupt or omit synthetic projection version then rebuild isolated vNext from retained source|Projection cannot authorize writes old view retained side effects suppressed source snapshot and abortable alias|Projection domain SRE and independent totals approver|SLO03 stale account or wrong synthetic exact value|Gap watermark source-target counts amounts build ID catch-up rate and alias condition|Gap detector opens and old view shows as-of marker|Park gap block cutover keep old view and isolate rebuild capacity|Abort on source mismatch external side effect live SLO harm or vNext wrong value|Delete only disposable vNext restore old alias and checkpoint evidence|No gaps exact totals source watermark and conditional alias compare pass|Validate source watermark exact totals and canary queries before alias switch|Original source and adjacent manifests build checkpoint query parity and approval|Unexecuted; record rebuild catch-up and cutover duration against SLO03 and DR04|Retention or source incompleteness makes rebuild impossible and remains OPEN; Inference: unexecuted local exercise policy from C117 C120 C122 C123; F39 and A132 A135 A137 retrieved 2026-08-23|FSR04 FSR09 RBK05 DR04 CASE09 RSP10 RSP14 INV08 INV09 INV10
EXERCISE|EX05|Regional or critical dependency loss with stale routing and fencing|Simulate route health failure and stale DNS or keepalive clients against non-production pre-provisioned Region|Backups manifests independent communications old and new writer kill switch no real provider effect and rollback authority|Incident commander platform command ledger external security compliance and stale-client observers|SLO01 unavailable until one writer then downstream SLO recovery|Business probes epoch conflict replication lag recovery-point age DNS cache keepalive KMS dependency readiness and replay age|Declared disaster condition and RTO clock start|Stop writes fence old Region recover authority-first withhold routing until stale probes deny|Abort on second writer missing RPO evidence ledger break or unsafe client acceptance|Return to last single-writer route only if fenced; otherwise keep unavailable|One epoch authority manifests RTO/RPO stale-client tests replay and exact totals pass|Canary read then write only after stale clients reject and one epoch is proven|Routing and epoch configs health timeline backup restore manifests and observer signoff|Unexecuted; objectives in DR01–DR05 remain unproven until measured|External dependency and corruption scenario may require different recovery; Inference: unexecuted local exercise policy from C117 C120 C122 C123; F39 and A132 A135 A137 retrieved 2026-08-23|FSR12 RBK08 DR01 DR02 DR03 DR04 DR05 CASE12 RSP14 INV10
EXERCISE|EX06|Credential compromise or break-glass misuse|Issue synthetic scoped credential then signal exfiltration or unauthorized break-glass query in isolated evidence set|No real secret or customer data revocation path pretested observer separates attacker and operator roles|Security IAM Audit Legal service owner and independent incident observer|Security interrupt plus possible SLO06 evidence access impact|Identity session CloudTrail application access audit token-vault lookup policy change and data query|Synthetic anomaly and access policy trigger|Disable identity revoke trust or session deny affected resources freeze change path|Abort if scope reaches real customer data production or revocation cannot be proven|Restore only reviewed role and rotate synthetic dependencies|All actions inventoried access denied after revoke evidence intact and reconciliation clean|Security and independent owner approve access tests and business reconciliation|Session policy principal actions query IDs revoke times approvals and investigation manifest|Unexecuted; planning restoration objective at most 15 min is unvalidated; when run record actual restoration plus detection/revocation duration and SLO06 eligible good budgeted-bad latency-bad burn and zero-tolerance access counters|Issued session or third-party copy can outlive immediate control; Inference: unexecuted local exercise policy from C117 C120 C122 C123; F39 and A132 A135 A137 retrieved 2026-08-23|SEC01 SEC07 SEC08 SEC09 CASE11 RSP01 RSP13 RSP14 INV08 INV09 INV10 SLO06
EXERCISE|EX07|Reconciliation discrepancy duplicate fill or ledger break|Inject synthetic duplicate execution missing posting or one-minor-unit imbalance into isolated controlled books|Exact units no production posting immutable original facts correction requires dual control and stop switch|Ledger operations execution owner reconciliation Compliance support and independent approver|SLO05 zero-tolerance break immediately|Duplicate execution ID debit-credit total reservation mismatch provider manifest and break state|Any injected discrepancy detected with correct scope|Freeze affected synthetic account or product writes preserve evidence prohibit blind mutation retry|Abort if scope grows authority uncertain evidence differs or automation attempts delete|Append linked reversal or correcting posting under exercise approval then re-run original and adjacent windows|Balanced exact totals execution reservation provider evidence and two-person VERIFIED then CLOSED|Resume synthetic writes only after independent VERIFIED state and adjacent-window check|Original and corrected postings source/provider manifests audit trail approvals and customer-state decision|Unexecuted; record detect contain correct verify duration against daily closure objective|Unknown authority or missing external statement leaves OPEN not force-closed; Inference: unexecuted local exercise policy from C117 C120 C122 C123; F39 and A132 A135 A137 retrieved 2026-08-23|FSR04 FSR07 FSR08 FSR11 RBK07 DR02 CASE07 CASE08 RSP05 RSP09 INV04 INV07

id	scenario	injection	safety	observers	symptom	signals	entry	containment	abort	restore	resume	proof	evidence	result	residual	routes
EX01	Queue or stream backlog and retry storm	Inject bounded synthetic slow dependency in non-production or isolated game-day lane; no customer or provider effects	Capacity reserve retention margin replay off switch synthetic identities and approved abort owner	Incident commander consumer dependency domain and observer-only reconciliation roles	SLO02 or SLO03 age burn while authority stays correct	Oldest age arrival commit and retry rates net drain throttles per-key fairness and manifest gap	Age crosses exercise threshold with authority probes green	Cap retry and replay shed optional work reserve live authority lane	Abort on safety break nonpositive drain retention margin or unrelated SLO harm	Remove injection restore configuration and checkpoint	Positive measured spare live age below gate and manifest population known	All admitted synthetic IDs resolved once versions and totals reconcile	Alarm timeline config versions replay manifest checkpoint and queries	Unexecuted; record measured drain time SLO burn and inferred recovery margin not vendor promise	Any expired or unresolved item remains OPEN; Inference: unexecuted local exercise policy from C117 C120 C122 C123; F39 and A132 A135 A137 retrieved 2026-08-23	FSR04 FSR06 FSR11 RBK03 DR03 CASE04 RSP03 RSP04 INV03 INV05
EX02	Poison or incompatible event	Publish signed synthetic unsupported schema into isolated key or replay sandbox	Full payload retained no external side effect ordered-lane isolation and known-good consumer retained	Schema producer consumer incident and domain observers	SLO02 gap for one synthetic key without unrelated-key starvation	Validation class receive count quarantine event source version iterator age and canary effect	One nonretryable validation or second identical failure	Quarantine exact payload isolate key and stop ordinary retry	Abort if payload escapes scope external call occurs or live age rises	Remove injection restore consumer or deploy tested compatible decoder	Offline dry run then one-key canary and source retention margin valid	Gap closes original identity retained transform lineage explicit and effects reconcile	Payload hash schema fixtures consumer versions quarantine and canary manifest	Unexecuted; record detection containment and recovery duration against SLO02	Semantically unsafe but schema-valid case remains test debt; Inference: unexecuted local exercise policy from C117 C120 C122 C123; F39 and A132 A135 A137 retrieved 2026-08-23	FSR05 RBK04 DR03 CASE05 RSP03 RSP12 INV03 INV06
EX03	DynamoDB throttle hot key and conditional contention	Synthetic account or key load with bounded provisioned fault or FIS-equivalent only in approved environment	No production authority mutation exact test ledger capacity ceiling stop token and per-key bulkhead	Domain capacity database and reconciliation observers	SLO01 latency or SLO03 freshness degrades for bounded cohort	ThrottledRequests correct dimensions throttle events conditional conflicts latency consumed capacity hot-key and business age	Synthetic threshold crossed and alarm routes to FSR08	Admission control per-key bulkhead reserve authority capacity and stop projection replay	Abort on unexpected table tenant production effect or exact-total mismatch	Remove load restore configuration and verify no lingering retries	Authority capacity and positive drain restored conditional decisions deterministic	One version per accepted command no duplicate posting and exact test totals balance	Load manifest key distribution metrics dimensions cancellation reasons and config	Unexecuted; record SLO impact recovery and capacity headroom	Real skew or single-key invariant may invalidate partition plan; Inference: unexecuted local exercise policy from C117 C120 C122 C123; F39 and A132 A135 A137 retrieved 2026-08-23	FSR08 FSR11 RBK03 DR01 DR02 CASE03 RSP01 RSP10 INV01 INV05
EX04	Broken or stale projection and vNext rebuild	Corrupt or omit synthetic projection version then rebuild isolated vNext from retained source	Projection cannot authorize writes old view retained side effects suppressed source snapshot and abortable alias	Projection domain SRE and independent totals approver	SLO03 stale account or wrong synthetic exact value	Gap watermark source-target counts amounts build ID catch-up rate and alias condition	Gap detector opens and old view shows as-of marker	Park gap block cutover keep old view and isolate rebuild capacity	Abort on source mismatch external side effect live SLO harm or vNext wrong value	Delete only disposable vNext restore old alias and checkpoint evidence	No gaps exact totals source watermark and conditional alias compare pass	Validate source watermark exact totals and canary queries before alias switch	Original source and adjacent manifests build checkpoint query parity and approval	Unexecuted; record rebuild catch-up and cutover duration against SLO03 and DR04	Retention or source incompleteness makes rebuild impossible and remains OPEN; Inference: unexecuted local exercise policy from C117 C120 C122 C123; F39 and A132 A135 A137 retrieved 2026-08-23	FSR04 FSR09 RBK05 DR04 CASE09 RSP10 RSP14 INV08 INV09 INV10
EX05	Regional or critical dependency loss with stale routing and fencing	Simulate route health failure and stale DNS or keepalive clients against non-production pre-provisioned Region	Backups manifests independent communications old and new writer kill switch no real provider effect and rollback authority	Incident commander platform command ledger external security compliance and stale-client observers	SLO01 unavailable until one writer then downstream SLO recovery	Business probes epoch conflict replication lag recovery-point age DNS cache keepalive KMS dependency readiness and replay age	Declared disaster condition and RTO clock start	Stop writes fence old Region recover authority-first withhold routing until stale probes deny	Abort on second writer missing RPO evidence ledger break or unsafe client acceptance	Return to last single-writer route only if fenced; otherwise keep unavailable	One epoch authority manifests RTO/RPO stale-client tests replay and exact totals pass	Canary read then write only after stale clients reject and one epoch is proven	Routing and epoch configs health timeline backup restore manifests and observer signoff	Unexecuted; objectives in DR01–DR05 remain unproven until measured	External dependency and corruption scenario may require different recovery; Inference: unexecuted local exercise policy from C117 C120 C122 C123; F39 and A132 A135 A137 retrieved 2026-08-23	FSR12 RBK08 DR01 DR02 DR03 DR04 DR05 CASE12 RSP14 INV10
EX06	Credential compromise or break-glass misuse	Issue synthetic scoped credential then signal exfiltration or unauthorized break-glass query in isolated evidence set	No real secret or customer data revocation path pretested observer separates attacker and operator roles	Security IAM Audit Legal service owner and independent incident observer	Security interrupt plus possible SLO06 evidence access impact	Identity session CloudTrail application access audit token-vault lookup policy change and data query	Synthetic anomaly and access policy trigger	Disable identity revoke trust or session deny affected resources freeze change path	Abort if scope reaches real customer data production or revocation cannot be proven	Restore only reviewed role and rotate synthetic dependencies	All actions inventoried access denied after revoke evidence intact and reconciliation clean	Security and independent owner approve access tests and business reconciliation	Session policy principal actions query IDs revoke times approvals and investigation manifest	Unexecuted; planning restoration objective at most 15 min is unvalidated; when run record actual restoration plus detection/revocation duration and SLO06 eligible good budgeted-bad latency-bad burn and zero-tolerance access counters	Issued session or third-party copy can outlive immediate control; Inference: unexecuted local exercise policy from C117 C120 C122 C123; F39 and A132 A135 A137 retrieved 2026-08-23	SEC01 SEC07 SEC08 SEC09 CASE11 RSP01 RSP13 RSP14 INV08 INV09 INV10 SLO06
EX07	Reconciliation discrepancy duplicate fill or ledger break	Inject synthetic duplicate execution missing posting or one-minor-unit imbalance into isolated controlled books	Exact units no production posting immutable original facts correction requires dual control and stop switch	Ledger operations execution owner reconciliation Compliance support and independent approver	SLO05 zero-tolerance break immediately	Duplicate execution ID debit-credit total reservation mismatch provider manifest and break state	Any injected discrepancy detected with correct scope	Freeze affected synthetic account or product writes preserve evidence prohibit blind mutation retry	Abort if scope grows authority uncertain evidence differs or automation attempts delete	Append linked reversal or correcting posting under exercise approval then re-run original and adjacent windows	Balanced exact totals execution reservation provider evidence and two-person VERIFIED then CLOSED	Resume synthetic writes only after independent VERIFIED state and adjacent-window check	Original and corrected postings source/provider manifests audit trail approvals and customer-state decision	Unexecuted; record detect contain correct verify duration against daily closure objective	Unknown authority or missing external statement leaves OPEN not force-closed; Inference: unexecuted local exercise policy from C117 C120 C122 C123; F39 and A132 A135 A137 retrieved 2026-08-23	FSR04 FSR07 FSR08 FSR11 RBK07 DR02 CASE07 CASE08 RSP05 RSP09 INV04 INV07

Decision table and architecture walkthroughs

Architecture labels here are chapter-local. In this operations chapter, ARCB denotes the explicit workflow with independently recoverable consumers. In trading architecture, ARCB denotes the replayable market/execution pipeline. Those are different descriptions in the original package, not an assertion that the topologies are identical. Read each walkthrough with its own component and authority boundaries.

Model details · task11 decision

DECISION|DEC01|Outcome SLO plus technical cause tree|Customer outcome can be measured at authority or durable receipt boundary and an owner can act|Tiny internal tool without meaningful outcome or owned response|More instrumentation and joins; avoids paging on irrelevant component noise|Eligible population or authority cannot be defined without circular telemetry|Manifest-to-SLI comparison and incident action success; Inference: local decision policy from C117 C118 C120 C122 C123; F39 F40 F41 and A132 A135 A137 retrieved 2026-08-23
DECISION|DEC02|Multi-window burn alert|High-volume ratio SLO where fast detection and false-positive control both matter|Zero-tolerance safety interrupt or traffic too sparse for stable ratios|More recording rules and tuning; separates fast symptom from slow policy|Historical incidents are missed or alert remains noisy at minimum traffic|Backtest against incidents and synthetic burn injection; Inference: local decision policy from C117 C118 C120 C122 C123; F39 F40 F41 and A132 A135 A137 retrieved 2026-08-23
DECISION|DEC03|Distributed tracing with sampled baggage allow-list|Latency crosses multiple services and causal diagnosis reduces repair time|Durable lineage audit proof or high-risk context cannot be safely propagated|Collector CPU memory egress and storage trade diagnostic depth against sampling bias|Known errors or slow paths vanish or sensitive context escapes|Propagation redaction and known-error sampling drills; Inference: local decision policy from C117 C118 C120 C122 C123; F39 F40 F41 and A132 A135 A137 retrieved 2026-08-23
DECISION|DEC04|Immutable evidence catalog and manifests|Named audit reconciliation or recovery assertion needs completeness and integrity|Unclassified debug output with no retention/legal owner|Unsampled storage KMS indexing and approvals cost more but support proof|Manifest population cannot be tied to named producers selectors and authority|Completeness reconciliation integrity validation and retrieval drill; Inference: local decision policy from C117 C118 C120 C122 C123; F39 F40 F41 and A132 A135 A137 retrieved 2026-08-23
DECISION|DEC05|Tenant-scoped credentials with pool or silo boundary|Multi-tenant access must be enforced at resource boundary and tested negatively|Anonymous public data with no tenant ownership|Pool is efficient but code-sensitive; silo reduces blast but adds accounts/deployments and still needs auth|Cross-tenant negative test succeeds or support/export path bypasses tenant predicate|Policy validation allowed/denied integration tests and access audit; Inference: local decision policy from C117 C118 C120 C122 C123; F39 F40 F41 and A132 A135 A137 retrieved 2026-08-23
DECISION|DEC06|Lambda alias canary with safety gates|Stateless compatible release has enough traffic and retained version|Irreversible schema or external effect cannot be isolated by traffic|Parallel versions and metrics cost; fast traffic stop but facts require reconciliation|Low volume hides error or shared downstream contaminates cohorts|Cohort manifests safety counters and retained rollback compatibility; Inference: local decision policy from C117 C118 C120 C122 C123; F39 F40 F41 and A132 A135 A137 retrieved 2026-08-23
DECISION|DEC07|Versioned vNext projection rebuild|Derived store can rebuild from durable authority without side effects|Store is authority source retention is incomplete or exact comparison unavailable|Double storage replay compute and spare capacity buy reversible cutover|Catch-up cannot finish inside retention or live SLO capacity margin|Full and adjacent manifests exact totals gaps watermark and alias condition; Inference: local decision policy from C117 C118 C120 C122 C123; F39 F40 F41 and A132 A135 A137 retrieved 2026-08-23
DECISION|DEC08|Pre-provisioned fenced regional recovery|Business RTO requires Region recovery and authority can enforce one writer|Corruption propagates or cost/complexity exceeds business objective|Duplicate capacity replication exercises and operations buy faster recovery but not zero loss|Game day cannot meet RTO/RPO or stale client reaches old writer|Measured recovery-point age duration one epoch stale-route probes and reconciliation; Inference: local decision policy from C117 C118 C120 C122 C123; F39 F40 F41 and A132 A135 A137 retrieved 2026-08-23

id	pattern	fit	poor_fit	tradeoff	falsifier	proof
DEC01	Outcome SLO plus technical cause tree	Customer outcome can be measured at authority or durable receipt boundary and an owner can act	Tiny internal tool without meaningful outcome or owned response	More instrumentation and joins; avoids paging on irrelevant component noise	Eligible population or authority cannot be defined without circular telemetry	Manifest-to-SLI comparison and incident action success; Inference: local decision policy from C117 C118 C120 C122 C123; F39 F40 F41 and A132 A135 A137 retrieved 2026-08-23
DEC02	Multi-window burn alert	High-volume ratio SLO where fast detection and false-positive control both matter	Zero-tolerance safety interrupt or traffic too sparse for stable ratios	More recording rules and tuning; separates fast symptom from slow policy	Historical incidents are missed or alert remains noisy at minimum traffic	Backtest against incidents and synthetic burn injection; Inference: local decision policy from C117 C118 C120 C122 C123; F39 F40 F41 and A132 A135 A137 retrieved 2026-08-23
DEC03	Distributed tracing with sampled baggage allow-list	Latency crosses multiple services and causal diagnosis reduces repair time	Durable lineage audit proof or high-risk context cannot be safely propagated	Collector CPU memory egress and storage trade diagnostic depth against sampling bias	Known errors or slow paths vanish or sensitive context escapes	Propagation redaction and known-error sampling drills; Inference: local decision policy from C117 C118 C120 C122 C123; F39 F40 F41 and A132 A135 A137 retrieved 2026-08-23
DEC04	Immutable evidence catalog and manifests	Named audit reconciliation or recovery assertion needs completeness and integrity	Unclassified debug output with no retention/legal owner	Unsampled storage KMS indexing and approvals cost more but support proof	Manifest population cannot be tied to named producers selectors and authority	Completeness reconciliation integrity validation and retrieval drill; Inference: local decision policy from C117 C118 C120 C122 C123; F39 F40 F41 and A132 A135 A137 retrieved 2026-08-23
DEC05	Tenant-scoped credentials with pool or silo boundary	Multi-tenant access must be enforced at resource boundary and tested negatively	Anonymous public data with no tenant ownership	Pool is efficient but code-sensitive; silo reduces blast but adds accounts/deployments and still needs auth	Cross-tenant negative test succeeds or support/export path bypasses tenant predicate	Policy validation allowed/denied integration tests and access audit; Inference: local decision policy from C117 C118 C120 C122 C123; F39 F40 F41 and A132 A135 A137 retrieved 2026-08-23
DEC06	Lambda alias canary with safety gates	Stateless compatible release has enough traffic and retained version	Irreversible schema or external effect cannot be isolated by traffic	Parallel versions and metrics cost; fast traffic stop but facts require reconciliation	Low volume hides error or shared downstream contaminates cohorts	Cohort manifests safety counters and retained rollback compatibility; Inference: local decision policy from C117 C118 C120 C122 C123; F39 F40 F41 and A132 A135 A137 retrieved 2026-08-23
DEC07	Versioned vNext projection rebuild	Derived store can rebuild from durable authority without side effects	Store is authority source retention is incomplete or exact comparison unavailable	Double storage replay compute and spare capacity buy reversible cutover	Catch-up cannot finish inside retention or live SLO capacity margin	Full and adjacent manifests exact totals gaps watermark and alias condition; Inference: local decision policy from C117 C118 C120 C122 C123; F39 F40 F41 and A132 A135 A137 retrieved 2026-08-23
DEC08	Pre-provisioned fenced regional recovery	Business RTO requires Region recovery and authority can enforce one writer	Corruption propagates or cost/complexity exceeds business objective	Duplicate capacity replication exercises and operations buy faster recovery but not zero loss	Game day cannot meet RTO/RPO or stale client reaches old writer	Measured recovery-point age duration one epoch stale-route probes and reconciliation; Inference: local decision policy from C117 C118 C120 C122 C123; F39 F40 F41 and A132 A135 A137 retrieved 2026-08-23

ARCA — durable serverless command and projection

The API dashboard starts with SLO01, unknown acceptances, and manifest balance; API Gateway/Lambda graphs diagnose, while the command record decides. DynamoDB transactions keep command/order/outbox intent together; Streams/outbox receipt, consumer inbox, source version, and SLO03 watermark expose propagation. REL01 canaries compatible Lambdas and REL05 rebuilds the portfolio in vNext. FSR01 routes to RBK01; FSR02/FSR03 to RBK02; projection incidents to RBK05. The architecture remains a poor fit for a latency-critical matching loop or invariants that cannot fit its transaction/serialization boundary. Inference: ARCA walkthrough and poor-fit conclusion derives from C99 C100 C112; F19 F20 and A115 retrieved 2026-08-22.

ARCB — explicit workflow and independently recoverable consumers

SLO01 still ends at command authority, not workflow success. A Step Functions history, callback token, task receipt, outbox/inbox, and provider request ID make each process state explainable; execution count metrics can repeat or be best-effort, so they remain diagnosis (C119, A130 retrieved 2026-08-23). FSR07 uses RBK06, never a blind external-effect retry. Flink, Firehose, or MSK signals appear only if that deployment actually uses them. Orchestration adds visible ownership and durable waits but increases state-machine, IAM, history, testing, and on-call surface; it is poor fit for a single local transaction or to conceal a hard cross-aggregate invariant. Inference: ARCB walkthrough and poor-fit conclusion derives from C101 C112 C119; F10 and A116 retrieved 2026-08-22; A130 retrieved 2026-08-23.

ARCC — fenced long-lived matcher with serverless surroundings

The matcher owns one journaled decision order per symbol/book scope and exposes decision/journal/epoch signals. SLO02 observes durable execution propagation, not merely low match latency. A release shadows deterministic decisions, fences the old epoch, promotes bounded symbols, and retains a reader-compatible binary (REL07). Surrounding command, ledger, notification, and projection paths reuse the same outbox/inbox/reconciliation controls. This design pays for resident capacity, standby, deployment/journal expertise, and failover exercises; it is poor fit when measured latency/throughput and recovery evidence do not justify that burden. Inference: ARCC walkthrough and poor-fit conclusion derives from C111 C112 C123; F09 retrieved 2026-08-22; A137 retrieved 2026-08-23.

Failure recovery cost and poor-fit analysis

Recovery begins by freezing the authority boundary that could amplify harm, classifying committed/unknown/not-attempted work, and preserving identity. It then restores dependency and writer safety, repairs from durable evidence under a bounded rate, proves exact outcomes, and only then resumes unrestricted traffic. “Alarm cleared,” “queue empty,” “function succeeded,” “replay finished,” and “Region switched” are intermediate facts, never closure proof.

Capacity and cost remain dimensioned:

• net_drain_per_second = measured_commit_capacity - live_arrival_rate - safety_reserve; replay is unsafe when this is non-positive.
• recovery_seconds = retained_repair_work / allocated_positive_net_drain; compare this with retention margin and SLO/RTO, never just monthly average cost.
• evidence_cost_per_closed_control = storage + ingestion + KMS + transfer + query_compute + allocated_engineering_and_on_call divided by closed clean windows plus owned open breaks.
• canary_overhead_ratio = parallel_version_compute_and_telemetry / steady_state_compute_and_telemetry; temporary cost is justified only by a meaningful stop/proof boundary.
• isolation_overhead_per_tenant = dedicated_accounts_resources_deployments_and_operations / protected_tenants; compare with measured cross-tenant risk and compliance requirements, not fashion.

Preserve Task 10's order: correctness and required auditability first, remove architectural waste second, tune configuration third, and change substrate only with workload evidence. Sampling audit evidence, dropping exact control totals, or under-provisioning authority to make the denominator cheaper is invalid.

Explicit poor fits and overclaims:

• An SLO has no value when the eligible population or owner cannot be defined; a component uptime average cannot stand in for acceptance or correctness.
• Trace context is a poor durable lineage store; high-cardinality customer IDs are poor metric dimensions; broad raw logs are a poor evidence catalog.
• A DLQ is a poor ledger, queue depth is a poor age/fairness measure, and invocation success is a poor protected-commit receipt.
• Encryption without resource authorization, WAF without authentication, private connectivity without identity, and account separation without tenant-scoped tests are incomplete security stories.
• A Lambda canary is poor protection for an irreversible migration whose old reader cannot parse newly written data; dual writes without a divergence contract are a poor atomicity strategy.
• Regional failover is a poor corruption recovery mechanism, and a DNS change is not writer fencing, data recovery, client retry safety, or reconciliation.

Senior interview articulation

Model details · task11 interview

INTERVIEW|IQ01|How do you define the order-acceptance SLO?|Good means one eligible logical command has a durable result within the window at command authority; latency and availability are separate and correctness is zero-tolerance|Explain fingerprint population exclusions unknown outcomes and manifest-derived measurement|API Gateway uptime or Lambda success equals acceptance|If authority and edge receipts cannot reconcile without dropping unknowns the SLO is not measurable; Inference: premises SLO01 C117; F14 F15 retrieved 2026-08-22; F39 retrieved 2026-08-23
INTERVIEW|IQ02|Why page on symptoms before causes?|A user or correctness symptom determines urgency; component signals locate cause and page only when an owner has an immediate action|Walk from SLO to FSR owner runbook containment and closure proof|Page every CPU queue-depth or error spike|If the cause alarm fires without impact or action repeatedly demote it to diagnosis; Inference: premises ALM01 ALM02 FSR01 FSR11 C117 C119; F39 A128 retrieved 2026-08-23
INTERVIEW|IQ03|What separates audit evidence from debug telemetry?|Audit evidence proves a named assertion over declared producers and completeness boundary with identity integrity retention and access; logs and traces can be sampled diagnostics|Discuss EVD01–EVD06 CloudTrail selectors manifests and legal hold|Object Lock CloudTrail or encrypted logs prove compliance and completeness|If a required record can be sampled or an unselected event is assumed present the claim fails; Inference: premises EVD01 EVD02 EVD03 SEC08 C109 C122; A41 A122 retrieved 2026-08-22; A135 retrieved 2026-08-23
INTERVIEW|IQ04|Can a trace ID be the idempotency or lineage key?|No; trace/span IDs are diagnostic and sampling-sensitive while command event execution and source-version IDs are durable at authority and inbox boundaries|Explain retry replay causation correlation and W3C baggage privacy|Unsafe: treating one sampled trace as exactly-once processing and audit history|Drop all traces in a replay and show business lineage still validates; Inference: premises IDENTITY trace command event C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
INTERVIEW|IQ05|How do you control observability cardinality and cost?|Keep raw business IDs in restricted indexed evidence and use bounded product region tier severity dimensions for metrics; sample diagnostics before correctness evidence|Discuss bytes per event series per cohort trace bias retention KMS transfer and on-call ratios|Put order account tenant and user ID on every metric for easy search|If series growth tracks customers or orders the dimension policy is unsafe; Inference: premises EVD04 EVD05 EVD06 C118 C119; F27 retrieved 2026-08-22; F40 F41 A139 A140 A141 A142 retrieved 2026-08-23
INTERVIEW|IQ06|Does a separate account or VPC prove tenant isolation?|No; it changes blast radius and operational boundary but authorization still binds authenticated tenant context to every resource access including indexes exports caches and support paths|Compare pool silo bridge scoped credentials policy conditions and negative tests|Multi-account or private subnet means isolation is solved|A cross-tenant negative test through any alternate path succeeds; Inference: premises SEC02 SEC03 SEC06 C120 C122; A38 A42 retrieved 2026-08-22; A136 A143 A144 retrieved 2026-08-23
INTERVIEW|IQ07|How do you release a replayable consumer safely?|Use compatible decoder retained raw input inbox idempotency isolated manifest bounded canary and external side-effect suppression or receipt lookup before replay|Explain stop conditions checkpoint capacity reserve and source-target reconciliation|Deploy then redrive the whole DLQ because consumers are idempotent|Any duplicate provider call or live-lane SLO burn stops replay; Inference: premises REL02 REL06 C99 C103 C123; F01 and A118 retrieved 2026-08-22; A137 retrieved 2026-08-23
INTERVIEW|IQ08|What is your first response to credential compromise?|Revoke identity and trust preserve evidence bound exposure freeze affected high-risk actions and reconcile ambiguous business effects before resume|Cover issued sessions secret rotation key grants break-glass audit and notification decision|Rotate the secret and close when authentication succeeds|An old session or provider credential still works or actions remain unaccounted; Inference: premises SEC01 SEC05 SEC07 SEC08 C120 C121 C122; A38 retrieved 2026-08-22; A132 A133 A134 A135 retrieved 2026-08-23
INTERVIEW|IQ09|How do you cut over a rebuilt projection?|Build isolated vNext from durable authority catch up compare versions counts exact values and watermark then conditionally switch while retaining old target|Explain why side effects are suppressed and how rollback differs from authority correction|Rebuild in place and switch when document counts match|Any gap amount difference build mismatch or live SLO pressure blocks cutover; Inference: premises REL05 RSP10 RSP14 C100 C123; F01 and A106 retrieved 2026-08-22; A137 retrieved 2026-08-23
INTERVIEW|IQ10|How do you recover a backlog without causing another outage?|Measure arrival and committed capacity reserve live and authority lanes replay only from positive net drain with abort thresholds and manifest checkpoints|Discuss oldest age skew fairness retention poison items and provider quotas|Raise concurrency until queue depth reaches zero|Net drain is non-positive or replay harms live SLO or reconciliation; Inference: premises FSR11 RBK03 C61 C104 C117; A117 A118 retrieved 2026-08-22; F39 retrieved 2026-08-23
INTERVIEW|IQ11|Why is reconciliation not just another retry?|It independently compares named authorities and exact units then classifies repairs and proves closure; retry only re-attempts one operation and can duplicate effects|Use duplicate fill missing posting provider ambiguity and adjacent-window control totals|Empty DLQ and green metrics mean the books reconcile|Any unexplained identity amount quantity version or provider difference remains; Inference: premises SLO05 INV06 INV07 C108 C117; F08 F17 F38 retrieved 2026-08-22
INTERVIEW|IQ12|What proves regional recovery?|One writer epoch stale-client rejection measured restoration duration recovery-point age or loss authority manifests replay and exact financial plus external reconciliation|Separate RTO RPO routing fencing corruption backup restore failback and unexecuted game-day status|DNS failover and healthy replicas prove zero loss|Second writer missing accepted ID breached RPO or dirty control total blocks service; Inference: premises FSR12 RBK08 DR01 C105 C106; A119 A120 A121 retrieved 2026-08-22

id	question	strong	deeper	unsafe	falsifier
IQ01	How do you define the order-acceptance SLO?	Good means one eligible logical command has a durable result within the window at command authority; latency and availability are separate and correctness is zero-tolerance	Explain fingerprint population exclusions unknown outcomes and manifest-derived measurement	API Gateway uptime or Lambda success equals acceptance	If authority and edge receipts cannot reconcile without dropping unknowns the SLO is not measurable; Inference: premises SLO01 C117; F14 F15 retrieved 2026-08-22; F39 retrieved 2026-08-23
IQ02	Why page on symptoms before causes?	A user or correctness symptom determines urgency; component signals locate cause and page only when an owner has an immediate action	Walk from SLO to FSR owner runbook containment and closure proof	Page every CPU queue-depth or error spike	If the cause alarm fires without impact or action repeatedly demote it to diagnosis; Inference: premises ALM01 ALM02 FSR01 FSR11 C117 C119; F39 A128 retrieved 2026-08-23
IQ03	What separates audit evidence from debug telemetry?	Audit evidence proves a named assertion over declared producers and completeness boundary with identity integrity retention and access; logs and traces can be sampled diagnostics	Discuss EVD01–EVD06 CloudTrail selectors manifests and legal hold	Object Lock CloudTrail or encrypted logs prove compliance and completeness	If a required record can be sampled or an unselected event is assumed present the claim fails; Inference: premises EVD01 EVD02 EVD03 SEC08 C109 C122; A41 A122 retrieved 2026-08-22; A135 retrieved 2026-08-23
IQ04	Can a trace ID be the idempotency or lineage key?	No; trace/span IDs are diagnostic and sampling-sensitive while command event execution and source-version IDs are durable at authority and inbox boundaries	Explain retry replay causation correlation and W3C baggage privacy	Unsafe: treating one sampled trace as exactly-once processing and audit history	Drop all traces in a replay and show business lineage still validates; Inference: premises IDENTITY trace command event C118; F27 retrieved 2026-08-22; F40 F41 retrieved 2026-08-23
IQ05	How do you control observability cardinality and cost?	Keep raw business IDs in restricted indexed evidence and use bounded product region tier severity dimensions for metrics; sample diagnostics before correctness evidence	Discuss bytes per event series per cohort trace bias retention KMS transfer and on-call ratios	Put order account tenant and user ID on every metric for easy search	If series growth tracks customers or orders the dimension policy is unsafe; Inference: premises EVD04 EVD05 EVD06 C118 C119; F27 retrieved 2026-08-22; F40 F41 A139 A140 A141 A142 retrieved 2026-08-23
IQ06	Does a separate account or VPC prove tenant isolation?	No; it changes blast radius and operational boundary but authorization still binds authenticated tenant context to every resource access including indexes exports caches and support paths	Compare pool silo bridge scoped credentials policy conditions and negative tests	Multi-account or private subnet means isolation is solved	A cross-tenant negative test through any alternate path succeeds; Inference: premises SEC02 SEC03 SEC06 C120 C122; A38 A42 retrieved 2026-08-22; A136 A143 A144 retrieved 2026-08-23
IQ07	How do you release a replayable consumer safely?	Use compatible decoder retained raw input inbox idempotency isolated manifest bounded canary and external side-effect suppression or receipt lookup before replay	Explain stop conditions checkpoint capacity reserve and source-target reconciliation	Deploy then redrive the whole DLQ because consumers are idempotent	Any duplicate provider call or live-lane SLO burn stops replay; Inference: premises REL02 REL06 C99 C103 C123; F01 and A118 retrieved 2026-08-22; A137 retrieved 2026-08-23
IQ08	What is your first response to credential compromise?	Revoke identity and trust preserve evidence bound exposure freeze affected high-risk actions and reconcile ambiguous business effects before resume	Cover issued sessions secret rotation key grants break-glass audit and notification decision	Rotate the secret and close when authentication succeeds	An old session or provider credential still works or actions remain unaccounted; Inference: premises SEC01 SEC05 SEC07 SEC08 C120 C121 C122; A38 retrieved 2026-08-22; A132 A133 A134 A135 retrieved 2026-08-23
IQ09	How do you cut over a rebuilt projection?	Build isolated vNext from durable authority catch up compare versions counts exact values and watermark then conditionally switch while retaining old target	Explain why side effects are suppressed and how rollback differs from authority correction	Rebuild in place and switch when document counts match	Any gap amount difference build mismatch or live SLO pressure blocks cutover; Inference: premises REL05 RSP10 RSP14 C100 C123; F01 and A106 retrieved 2026-08-22; A137 retrieved 2026-08-23
IQ10	How do you recover a backlog without causing another outage?	Measure arrival and committed capacity reserve live and authority lanes replay only from positive net drain with abort thresholds and manifest checkpoints	Discuss oldest age skew fairness retention poison items and provider quotas	Raise concurrency until queue depth reaches zero	Net drain is non-positive or replay harms live SLO or reconciliation; Inference: premises FSR11 RBK03 C61 C104 C117; A117 A118 retrieved 2026-08-22; F39 retrieved 2026-08-23
IQ11	Why is reconciliation not just another retry?	It independently compares named authorities and exact units then classifies repairs and proves closure; retry only re-attempts one operation and can duplicate effects	Use duplicate fill missing posting provider ambiguity and adjacent-window control totals	Empty DLQ and green metrics mean the books reconcile	Any unexplained identity amount quantity version or provider difference remains; Inference: premises SLO05 INV06 INV07 C108 C117; F08 F17 F38 retrieved 2026-08-22
IQ12	What proves regional recovery?	One writer epoch stale-client rejection measured restoration duration recovery-point age or loss authority manifests replay and exact financial plus external reconciliation	Separate RTO RPO routing fencing corruption backup restore failback and unexecuted game-day status	DNS failover and healthy replicas prove zero loss	Second writer missing accepted ID breached RPO or dirty control total blocks service; Inference: premises FSR12 RBK08 DR01 C105 C106; A119 A120 A121 retrieved 2026-08-22

The strong-answer pattern is stable: name the user outcome and authority, bound the guarantee, state the failure/repair owner, quantify workload and cost, and finish with evidence that could prove the design wrong.

Sources used in this chapter

New stable routes retrieved 2026-08-23 are Google SRE multi-window/multi-burn alerting (F39), W3C Trace Context (F40), and W3C Baggage (F41). Existing stable SRE, retry, overload, schema, tracing, and domain routes remain F01, F03, F08, F11–F16, F17, F25–F27.

New mutable first-party routes, each retrieved 2026-08-23, are API Gateway metrics (A128), DynamoDB metrics (A129), Step Functions metrics (A130), Firehose metrics (A131), IAM policy validation (A132), KMS key policy/encryption context (A133), Secrets Manager rotation (A134), CloudTrail event scopes (A135), SaaS tenant isolation/topologies (A136), Lambda alias/CodeDeploy release mechanics (A137), the Well-Architected Security Pillar (A138), Lambda metrics (A139), EventBridge metrics (A140), SQS metrics (A141), SNS metrics (A142), IAM confused-deputy conditions (A143), and WAF association scope (A144). Existing 2026-08-22 snapshots retain their original dates: A36–A42, A81, A119–A122. Controlled claims used are C43–C50, C57, C59, C61, C68, C90, C99–C106, C109, and C117–C123.

SSE cross-reference: the six local SRE/observability notes prompted checks for SLIs, burn alerts, correlation, and log/metric/trace trade-offs. They remain cross-reference evidence only; none of their thresholds or percentages is an authority for this chapter.

Takeaway and next step

Operational readiness means an outcome has a measurable population, an owner can respond, and recovery can be proved against authority. Explain the order SLO without dropping unknowns; distinguish sampled diagnostics from complete evidence; and describe a compatible release or fenced recovery. Now close the notes and work through Interview practice and self-assessment, returning to these chapters for any weak boundary.