{ "policy": { "version": 5, "patterns": { "version": 1, "method": "CURATED_PRACTICE_TOPIC", "notice": "Pattern topics identify design choices to practice. Read the ticket's acceptance criteria and justify the simplest suitable approach. Tags are not capability or ownership evidence; an untagged ticket has no curated pattern topic assigned." }, "fieldMix": { "version": 1, "method": "CURATED_ESTIMATE", "notice": "Field percentages are editorial estimates of the ticket's engineering focus. They total 100%; they are not measured time, proficiency scores, or ownership evidence." }, "contentStatus": "PRACTICE_BRIEF", "assessmentStatus": "NOT_QUALIFIED", "evidenceUse": "NONE", "aiPolicy": "AI tools are welcome during implementation. Record assumptions, review the result, and verify its behavior.", "notice": "Fictional engineering practice briefs. Starter repositories, fixtures, automated grading, and verified ownership are not included.", "outcomeEvidence": "Tests, patches, and runbooks are requested deliverables. They become Outcome Evidence only through a qualified Mission and immutable Evidence IDs.", "ownershipEvidence": "Independent adaptation must be observed under a declared verification policy and cite immutable Evidence IDs. Completing a planning ticket establishes no Ownership Evidence." }, "patternTopics": [ { "id": "factory-method", "label": "Factory Method", "group": "Creational" }, { "id": "abstract-factory", "label": "Abstract Factory", "group": "Creational" }, { "id": "builder", "label": "Builder", "group": "Creational" }, { "id": "prototype", "label": "Prototype", "group": "Creational" }, { "id": "singleton", "label": "Singleton", "group": "Creational" }, { "id": "adapter", "label": "Adapter", "group": "Structural" }, { "id": "bridge", "label": "Bridge", "group": "Structural" }, { "id": "composite", "label": "Composite", "group": "Structural" }, { "id": "decorator", "label": "Decorator", "group": "Structural" }, { "id": "facade", "label": "Facade", "group": "Structural" }, { "id": "flyweight", "label": "Flyweight", "group": "Structural" }, { "id": "proxy", "label": "Proxy", "group": "Structural" }, { "id": "chain-of-responsibility", "label": "Chain of Responsibility", "group": "Behavioral" }, { "id": "command", "label": "Command", "group": "Behavioral" }, { "id": "interpreter", "label": "Interpreter", "group": "Behavioral" }, { "id": "iterator", "label": "Iterator", "group": "Behavioral" }, { "id": "mediator", "label": "Mediator", "group": "Behavioral" }, { "id": "memento", "label": "Memento", "group": "Behavioral" }, { "id": "observer", "label": "Observer", "group": "Behavioral" }, { "id": "state", "label": "State", "group": "Behavioral" }, { "id": "strategy", "label": "Strategy", "group": "Behavioral" }, { "id": "template-method", "label": "Template Method", "group": "Behavioral" }, { "id": "visitor", "label": "Visitor", "group": "Behavioral" }, { "id": "ports-and-adapters", "label": "Ports and Adapters", "group": "Architectural" }, { "id": "cqrs", "label": "CQRS", "group": "Architectural" }, { "id": "strangler-fig", "label": "Strangler Fig", "group": "Architectural" }, { "id": "saga", "label": "Saga", "group": "Distributed and reliability" }, { "id": "transactional-outbox", "label": "Transactional Outbox", "group": "Distributed and reliability" }, { "id": "circuit-breaker", "label": "Circuit Breaker", "group": "Distributed and reliability" }, { "id": "bulkhead", "label": "Bulkhead", "group": "Distributed and reliability" } ], "projects": [ { "id": "ebf9937a-23c7-42f3-8025-beea18139db6", "key": "ARESTORE", "title": "Prove a PostgreSQL backup can restore usable application state", "field": "Database engineering", "summary": "Build a bounded backup inventory and rehearse restoration with consistency checks.", "context": "A fictional case-management team has nightly backup files but has never tested application behavior after restore. Missing roles and external artifact references may make a successful database restore unusable.", "stack": [ "PostgreSQL", "TypeScript", "Object storage" ], "prerequisites": [ "Create a disposable synthetic database and local backup directory.", "Never connect these drills to production or overwrite a shared database." ], "developerValue": "Practice restore verification, provenance and operational recovery.", "companyValue": "Review evidence that recovery produces coherent usable state under declared limits.", "delivery": "Ten scoped tickets across three phases. Build a synthetic local service or select a ticket after recreating its prerequisites; estimates exclude setup.", "phases": [ { "id": "inventory", "title": "Identify recovery inputs", "goal": "Record backup identity and application dependencies." }, { "id": "restore", "title": "Restore and verify", "goal": "Use isolated targets and validate relational/application state." }, { "id": "drill", "title": "Exercise recovery failures", "goal": "Measure local recovery and document missing guarantees." } ], "tickets": [ { "id": "7a445df7-5e4f-4f6a-8611-da4b2edb8cb2", "key": "ARESTORE-101", "title": "Inventory database recovery inputs beyond the dump file", "type": "TASK", "priority": "MEDIUM", "difficulty": "FOUNDATIONAL", "estimateMinutes": 90, "phaseId": "inventory", "dependsOn": [], "scenario": "A test restore contains tables but cannot start the application because expected roles and extensions are absent.", "acceptanceCriteria": [ "List schema, roles, extensions, migration version and artifact dependencies.", "Separate secret configuration from backup contents.", "Record unresolved dependencies explicitly." ], "implementationNotes": [ "Use a disposable synthetic database with a minimal application." ], "verification": [ "Start the application from a complete declared inventory.", "Omit an extension in a fixture and identify the missing prerequisite." ], "deliverables": [ "Recovery dependency inventory" ], "rollout": "Review inventory before claiming restore readiness; keep unresolved prerequisites visible.", "skills": [ "Backup planning", "Database operations" ], "fieldMix": [ { "field": "Database engineering", "percentage": 60 }, { "field": "Site reliability", "percentage": 20 }, { "field": "Storage systems", "percentage": 20 } ], "patterns": [] }, { "id": "16c4cb2b-8dea-40f5-8727-ec340da53f70", "key": "ARESTORE-102", "title": "Create a backup manifest that binds bytes to schema revision", "type": "TASK", "priority": "MEDIUM", "difficulty": "INTERMEDIATE", "estimateMinutes": 150, "phaseId": "inventory", "dependsOn": [ "ARESTORE-101" ], "scenario": "Operators find three similarly named dump files and cannot tell which migration version or time each represents.", "acceptanceCriteria": [ "Record byte hash, size, UTC capture time and migration identity.", "Bind the manifest to the exact backup artifact.", "Reject a missing or mismatched manifest before restore." ], "implementationNotes": [ "Use synthetic data and avoid credentials in command logs." ], "verification": [ "Verify a backup and matching manifest.", "Alter backup bytes and reject the restore plan." ], "deliverables": [ "Backup manifest command and integrity checks" ], "rollout": "Create manifests for new backups; label unverified older files as uncertain.", "skills": [ "Provenance", "Checksums" ], "fieldMix": [ { "field": "Database engineering", "percentage": 60 }, { "field": "Storage systems", "percentage": 40 } ], "patterns": [] }, { "id": "11a15c93-1e1f-4e3d-bf32-4bd895312a56", "key": "ARESTORE-103", "title": "Validate that a restore target is isolated before running destructive steps", "type": "TASK", "priority": "HIGH", "difficulty": "FOUNDATIONAL", "estimateMinutes": 90, "phaseId": "inventory", "dependsOn": [ "ARESTORE-101", "ARESTORE-102" ], "scenario": "A copied restore command could replace the development database instead of the disposable drill target.", "acceptanceCriteria": [ "Require an explicit disposable target identity and expected marker.", "Resolve and inspect target connection metadata before mutation.", "Reject shared, production-like or unmarked targets." ], "implementationNotes": [ "Use exact database names and task-specific credentials; no wildcard cleanup." ], "verification": [ "Plan a restore to a marked disposable target.", "Point at an unmarked synthetic target and verify zero destructive calls." ], "deliverables": [ "Restore-target guard and denial tests" ], "rollout": "Make the guard mandatory for drills; abort if target identity changes.", "skills": [ "Operational safety", "Input validation" ], "fieldMix": [ { "field": "Database engineering", "percentage": 50 }, { "field": "Security", "percentage": 50 } ], "patterns": [] }, { "id": "668f52de-40a3-4cac-8ad7-381e43955761", "key": "ARESTORE-104", "title": "Restore a verified backup into a new database generation", "type": "STORY", "priority": "MEDIUM", "difficulty": "ADVANCED", "estimateMinutes": 240, "phaseId": "restore", "dependsOn": [ "ARESTORE-102", "ARESTORE-103" ], "scenario": "The current procedure restores directly over the active database and leaves no usable environment if it fails halfway.", "acceptanceCriteria": [ "Create and restore into a distinct verified disposable generation.", "Keep the prior target untouched until checks complete.", "Record each restore stage and failure without exposing data contents." ], "implementationNotes": [ "Use bounded local synthetic backups only." ], "verification": [ "Restore a valid backup and inspect the new generation.", "Fail mid-restore and verify the previous synthetic application still reads its original database." ], "deliverables": [ "Generation-based restore script" ], "rollout": "Use a new target for every drill; remove only verified owned failed generations after review.", "skills": [ "Recovery isolation", "Database restore" ], "fieldMix": [ { "field": "Database engineering", "percentage": 70 }, { "field": "Site reliability", "percentage": 30 } ], "patterns": [] }, { "id": "d91de79b-a890-44e2-975e-34ea6653dc28", "key": "ARESTORE-105", "title": "Check relational invariants after restoration", "type": "TASK", "priority": "MEDIUM", "difficulty": "INTERMEDIATE", "estimateMinutes": 180, "phaseId": "restore", "dependsOn": [ "ARESTORE-104" ], "scenario": "A restore exits successfully but an earlier disabled constraint allowed orphan case assignments into the backup.", "acceptanceCriteria": [ "Check expected foreign keys, unique constraints and required indexes.", "Run explicit orphan and duplicate queries on restored data.", "Fail application activation when invariants do not hold." ], "implementationNotes": [ "Compare actual catalog metadata with the declared migration contract." ], "verification": [ "Validate a clean synthetic restored database.", "Restore a deliberately inconsistent fixture and report exact invariant failures." ], "deliverables": [ "Post-restore SQL verification suite" ], "rollout": "Run before connecting application traffic; retain the failed generation for bounded diagnosis.", "skills": [ "Relational integrity", "Schema verification" ], "fieldMix": [ { "field": "Database engineering", "percentage": 70 }, { "field": "Quality engineering", "percentage": 30 } ], "patterns": [] }, { "id": "90bef672-ef52-4112-aa7b-48e2e8beff7c", "key": "ARESTORE-106", "title": "Reconcile restored database references with external artifacts", "type": "TASK", "priority": "MEDIUM", "difficulty": "ADVANCED", "estimateMinutes": 240, "phaseId": "restore", "dependsOn": [ "ARESTORE-101", "ARESTORE-104", "ARESTORE-105" ], "scenario": "Case attachments point to objects created after the backup cutoff, and some objects referenced by restored rows are missing.", "acceptanceCriteria": [ "Compare immutable object versions and hashes for referenced artifacts.", "Report missing, extra and mismatched objects separately.", "Do not replace missing artifacts with similarly named current objects." ], "implementationNotes": [ "Use a local object-store fixture and explicit backup cutoff." ], "verification": [ "Restore matching database and object manifests.", "Remove a referenced object and keep the application readiness result incomplete." ], "deliverables": [ "Artifact reconciliation command" ], "rollout": "Keep artifact-dependent routes unavailable until their references verify; preserve missing-reference reports.", "skills": [ "Cross-store consistency", "Recovery" ], "fieldMix": [ { "field": "Database engineering", "percentage": 40 }, { "field": "Storage systems", "percentage": 40 }, { "field": "Distributed systems", "percentage": 20 } ], "patterns": [] }, { "id": "dd671a74-9fa9-4b34-8fbd-b44ca4672f18", "key": "ARESTORE-107", "title": "Prevent post-restore background jobs from repeating completed side effects", "type": "TASK", "priority": "HIGH", "difficulty": "EXPERT", "estimateMinutes": 360, "phaseId": "restore", "dependsOn": [ "ARESTORE-104", "ARESTORE-105", "ARESTORE-106" ], "scenario": "A restored outbox contains delivery records whose external effects happened after the database backup but before the outage.", "acceptanceCriteria": [ "Document the database/external-side-effect recovery gap.", "Reconcile provider identities before redispatching restored records.", "Preserve unknown outcomes rather than asserting they were never sent." ], "implementationNotes": [ "Use fake providers with durable synthetic request identities; send no messages." ], "verification": [ "Restore a completed external operation and reconcile it without duplication.", "Make provider status unavailable and keep redispatch blocked under the declared policy." ], "deliverables": [ "Outbox recovery protocol and provider probe" ], "rollout": "Start restored workers paused; release only reconciled work and retain unknown cases.", "skills": [ "Distributed recovery", "Idempotency" ], "fieldMix": [ { "field": "Distributed systems", "percentage": 50 }, { "field": "Database engineering", "percentage": 30 }, { "field": "Site reliability", "percentage": 20 } ], "patterns": [] }, { "id": "cebd3782-1dc6-4c3b-9ddf-4f3f519a05eb", "key": "ARESTORE-108", "title": "Measure local restore time with complete verification included", "type": "CHORE", "priority": "MEDIUM", "difficulty": "INTERMEDIATE", "estimateMinutes": 180, "phaseId": "drill", "dependsOn": [ "ARESTORE-104", "ARESTORE-105", "ARESTORE-106", "ARESTORE-107" ], "scenario": "The team's restore-time figure measures only dump loading and excludes artifact checks and application readiness.", "acceptanceCriteria": [ "Record hardware, versions, dataset size and cache conditions.", "Measure load, verification and readiness stages separately.", "Repeat the same synthetic restore three times and report spread." ], "implementationNotes": [ "These observations do not establish a production RTO." ], "verification": [ "Run the declared complete restore drill and record all stages.", "Fail an invariant check and report recovery incomplete despite dump success." ], "deliverables": [ "Reproducible local restore timing report" ], "rollout": "Use measurements to improve the drill; revise targets only after representative environment testing.", "skills": [ "Operational measurement", "Recovery objectives" ], "fieldMix": [ { "field": "Site reliability", "percentage": 40 }, { "field": "Database engineering", "percentage": 40 }, { "field": "Performance engineering", "percentage": 20 } ], "patterns": [] }, { "id": "ab6f17ec-2fa5-4902-8c5f-fcdb52823325", "key": "ARESTORE-109", "title": "Rehearse backup corruption and missing-manifest failure paths", "type": "TASK", "priority": "MEDIUM", "difficulty": "EXPERT", "estimateMinutes": 300, "phaseId": "drill", "dependsOn": [ "ARESTORE-102", "ARESTORE-103", "ARESTORE-108" ], "scenario": "Operators need a practiced response when the newest backup is unusable rather than trying increasingly risky manual restore commands.", "acceptanceCriteria": [ "Reject corrupt artifacts before activating a generation.", "Select an earlier verified backup with an explicit data-gap statement.", "Record the cutoff and unresolved external effects." ], "implementationNotes": [ "Create disposable corrupted copies rather than altering the retained good backup." ], "verification": [ "Restore from the prior verified synthetic backup.", "Present a missing manifest and corrupted newest artifact and keep both untrusted." ], "deliverables": [ "Backup-failure drill and recovery decision trace" ], "rollout": "Run periodically in disposable targets; preserve good backups and stop when no verified candidate exists.", "skills": [ "Recovery planning", "Integrity" ], "fieldMix": [ { "field": "Database engineering", "percentage": 50 }, { "field": "Site reliability", "percentage": 30 }, { "field": "Storage systems", "percentage": 20 } ], "patterns": [] }, { "id": "e70f56ef-c614-4412-8a35-2a93c235c6ae", "key": "ARESTORE-110", "title": "Write an application-level database recovery handoff", "type": "TASK", "priority": "MEDIUM", "difficulty": "FOUNDATIONAL", "estimateMinutes": 90, "phaseId": "drill", "dependsOn": [ "ARESTORE-107", "ARESTORE-108", "ARESTORE-109" ], "scenario": "A successful command transcript is handed to on-call staff without clear activation criteria or a statement of potentially missing data.", "acceptanceCriteria": [ "List verification gates and the selected recovery cutoff.", "Include worker pause/release and artifact availability steps.", "State measured local limits and unresolved production dependencies." ], "implementationNotes": [ "Use fabricated case records in the worked example." ], "verification": [ "Follow the handoff from verified backup to synthetic application readiness.", "Follow the no-verified-backup branch and stop without claiming recovery." ], "deliverables": [ "Recovery runbook and worked handoff" ], "rollout": "Review with a fresh local drill; update the runbook when schema or provider contracts change.", "skills": [ "Runbooks", "Recovery communication" ], "fieldMix": [ { "field": "Database engineering", "percentage": 60 }, { "field": "Site reliability", "percentage": 40 } ], "patterns": [] } ] } ] }