{ "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": "5951c8eb-f3ff-4d2e-a159-df7597aa8a15", "key": "BRESTORE", "title": "Backup restoration rehearsal", "field": "Site reliability", "summary": "Verify that database and object-store backups can reconstruct a coherent service.", "context": "A fictional reporting service has successful backup jobs but no recent restore rehearsal. Database rows reference objects with different retention schedules.", "stack": [ "PostgreSQL", "S3-compatible storage", "TypeScript" ], "prerequisites": [ "Create disposable local database and object-store fixtures with synthetic reports; author backup and corruption examples." ], "developerValue": "Practice recovery consistency, integrity validation, and honest recovery objectives.", "companyValue": "Replace backup-job optimism with a repeatable restoration assessment.", "delivery": "Deliver a local restore harness and recovery report; change no production backup policy.", "phases": [ { "id": "inventory", "title": "Inventory recovery dependencies", "goal": "Define backup scope and consistency requirements." }, { "id": "restore", "title": "Restore isolated data", "goal": "Reconstruct and validate a coherent snapshot." }, { "id": "prove", "title": "Rehearse disruption", "goal": "Measure recovery and document unrecoverable gaps." } ], "tickets": [ { "id": "0ee5a2c7-d2e6-44cb-9924-b80e3247c9f3", "key": "BRESTORE-101", "title": "Inventory the data required to restore one report", "type": "TASK", "priority": "MEDIUM", "difficulty": "FOUNDATIONAL", "estimateMinutes": 60, "phaseId": "inventory", "dependsOn": [], "scenario": "A database backup omits the object containing the actual report.", "acceptanceCriteria": [ "List database rows, objects, and configuration references.", "Identify authoritative and rebuildable data.", "Document retention mismatches." ], "implementationNotes": [ "Use synthetic records and secret placeholders." ], "verification": [ "Trace one report end to end.", "Identify a missing object as an incomplete recovery dependency." ], "deliverables": [ "Recovery inventory." ], "rollout": "Review inventory before altering backup jobs.", "skills": [ "Recovery planning" ], "fieldMix": [ { "field": "Site reliability", "percentage": 50 }, { "field": "Storage systems", "percentage": 30 }, { "field": "Database engineering", "percentage": 20 } ], "patterns": [] }, { "id": "cb85c00a-328e-43ab-b224-3cca5203b5a0", "key": "BRESTORE-102", "title": "Define a consistent backup manifest across stores", "type": "TASK", "priority": "HIGH", "difficulty": "ADVANCED", "estimateMinutes": 180, "phaseId": "inventory", "dependsOn": [ "BRESTORE-101" ], "scenario": "Database and object backups represent different points in time.", "acceptanceCriteria": [ "Record snapshot boundary and object version digests.", "Include schema and manifest versions.", "Reject incomplete manifests." ], "implementationNotes": [ "Do not equate wall-clock proximity with transactional consistency." ], "verification": [ "Build a coherent synthetic manifest.", "Reject a manifest referencing an unavailable object version." ], "deliverables": [ "Backup manifest contract." ], "rollout": "Version manifests and retain the prior complete backup set.", "skills": [ "Consistency", "Provenance" ], "fieldMix": [ { "field": "Storage systems", "percentage": 50 }, { "field": "Database engineering", "percentage": 30 }, { "field": "Site reliability", "percentage": 20 } ], "patterns": [] }, { "id": "b9650b0e-1c8b-4292-92c3-0d7923300b8a", "key": "BRESTORE-103", "title": "Guard restore commands against non-scratch targets", "type": "TASK", "priority": "HIGH", "difficulty": "INTERMEDIATE", "estimateMinutes": 120, "phaseId": "restore", "dependsOn": [ "BRESTORE-102" ], "scenario": "A restore command can overwrite an existing developer database by mistake.", "acceptanceCriteria": [ "Require an explicit scratch target.", "Reject nonempty or unapproved destinations.", "Display sanitized target identity." ], "implementationNotes": [ "No remote or production endpoints in this exercise." ], "verification": [ "Restore into an empty named scratch database.", "Reject an occupied or remote destination." ], "deliverables": [ "Restore target guard." ], "rollout": "Default to inspection-only until target validation passes.", "skills": [ "Operational safety" ], "fieldMix": [ { "field": "Developer tooling", "percentage": 50 }, { "field": "Site reliability", "percentage": 30 }, { "field": "Security", "percentage": 20 } ], "patterns": [] }, { "id": "47c47925-5172-422a-afdf-19c488a9d82f", "key": "BRESTORE-104", "title": "Verify backup bytes before applying restored data", "type": "TASK", "priority": "HIGH", "difficulty": "INTERMEDIATE", "estimateMinutes": 120, "phaseId": "restore", "dependsOn": [ "BRESTORE-102", "BRESTORE-103" ], "scenario": "A truncated object archive is discovered only after the application starts.", "acceptanceCriteria": [ "Validate declared sizes and content digests.", "Reject missing or extra required archive members.", "Stop before promotion on any mismatch." ], "implementationNotes": [ "Bound archive expansion and reject traversal paths." ], "verification": [ "Verify a complete backup set.", "Reject corruption and an escaping archive entry." ], "deliverables": [ "Backup integrity verifier." ], "rollout": "Keep failed restores isolated and retain diagnostic metadata.", "skills": [ "Integrity", "Archive handling" ], "fieldMix": [ { "field": "Storage systems", "percentage": 70 }, { "field": "Site reliability", "percentage": 30 } ], "patterns": [] }, { "id": "4ba8ef07-7084-4fff-89e3-a8bb0c104332", "key": "BRESTORE-105", "title": "Restore database references before enabling object reads", "type": "TASK", "priority": "HIGH", "difficulty": "ADVANCED", "estimateMinutes": 180, "phaseId": "restore", "dependsOn": [ "BRESTORE-104" ], "scenario": "The application exposes restored metadata while referenced objects are still missing.", "acceptanceCriteria": [ "Keep restored service unavailable until coherence checks pass.", "Reconcile every required object reference.", "Report dangling references without inventing replacements." ], "implementationNotes": [ "Public readiness must not imply partial data is complete." ], "verification": [ "Restore a coherent report set.", "Remove one object and keep readiness blocked." ], "deliverables": [ "Restore readiness checks." ], "rollout": "Promote only a validated restore; preserve the original scratch failure state.", "skills": [ "Readiness", "Data integrity" ], "fieldMix": [ { "field": "Site reliability", "percentage": 40 }, { "field": "Database engineering", "percentage": 30 }, { "field": "Storage systems", "percentage": 30 } ], "patterns": [] }, { "id": "b233188d-9f99-42ab-9828-9bc7a9d0ebc4", "key": "BRESTORE-106", "title": "Rebuild derived indexes from restored authoritative records", "type": "TASK", "priority": "MEDIUM", "difficulty": "ADVANCED", "estimateMinutes": 180, "phaseId": "restore", "dependsOn": [ "BRESTORE-105" ], "scenario": "The backup contains stale search indexes that disagree with restored reports.", "acceptanceCriteria": [ "Rebuild indexes from the restored authority.", "Make rebuild restartable and bounded.", "Verify index counts and sampled content bindings." ], "implementationNotes": [ "Never treat an index as the source of truth." ], "verification": [ "Rebuild after a complete restore.", "Interrupt rebuilding and resume without duplicate entries." ], "deliverables": [ "Derived-data rebuild command." ], "rollout": "Keep search unavailable until its version matches restored data.", "skills": [ "Data recovery", "Indexing" ], "fieldMix": [ { "field": "Data engineering", "percentage": 60 }, { "field": "Site reliability", "percentage": 40 } ], "patterns": [] }, { "id": "92514dc4-34d8-4207-9576-2abbc636060d", "key": "BRESTORE-107", "title": "Check application compatibility against restored schema versions", "type": "TASK", "priority": "HIGH", "difficulty": "ADVANCED", "estimateMinutes": 180, "phaseId": "prove", "dependsOn": [ "BRESTORE-105", "BRESTORE-106" ], "scenario": "The latest application cannot read a backup taken before a schema contraction.", "acceptanceCriteria": [ "Declare compatible application/schema pairs.", "Run representative reads and writes after restore.", "Identify migration requirements before promotion." ], "implementationNotes": [ "Do not silently upgrade restored data without a reviewed path." ], "verification": [ "Start a compatible build against the restore.", "Reject an incompatible schema with clear guidance." ], "deliverables": [ "Restore compatibility matrix." ], "rollout": "Retain a compatible application artifact with each backup generation.", "skills": [ "Schema evolution" ], "fieldMix": [ { "field": "Database engineering", "percentage": 60 }, { "field": "Site reliability", "percentage": 40 } ], "patterns": [] }, { "id": "80bb26c3-b7cc-4990-8344-6c5cae8578a9", "key": "BRESTORE-108", "title": "Measure recovery time and recoverable data loss separately", "type": "TASK", "priority": "HIGH", "difficulty": "EXPERT", "estimateMinutes": 300, "phaseId": "prove", "dependsOn": [ "BRESTORE-107" ], "scenario": "Management asks for recovery objectives, but a single successful local restore is being treated as a guarantee.", "acceptanceCriteria": [ "Measure each restore phase under stated dataset and machine limits.", "Compute the gap between backup boundary and failure time.", "Report untested scale and dependency assumptions." ], "implementationNotes": [ "Local rehearsal establishes observations, not production RTO or RPO guarantees." ], "verification": [ "Measure a complete synthetic recovery.", "Expose an unrecoverable post-backup write explicitly." ], "deliverables": [ "Recovery assessment." ], "rollout": "Use results to propose objectives; repeat in the target environment before committing to them.", "skills": [ "Reliability planning", "Experimental design" ], "fieldMix": [ { "field": "Site reliability", "percentage": 60 }, { "field": "Performance engineering", "percentage": 40 } ], "patterns": [] }, { "id": "e254c6b8-e2ca-47d8-98d7-c7556dde8bbd", "key": "BRESTORE-109", "title": "Rehearse recovery when the newest backup is unusable", "type": "TASK", "priority": "HIGH", "difficulty": "ADVANCED", "estimateMinutes": 180, "phaseId": "prove", "dependsOn": [ "BRESTORE-104", "BRESTORE-108" ], "scenario": "The latest backup manifest is valid but one required object version is unavailable.", "acceptanceCriteria": [ "Select an older complete recovery set explicitly.", "Report the increased data-loss window.", "Preserve evidence of why the newest set was rejected." ], "implementationNotes": [ "Never merge unrelated backup generations without a defined consistency rule." ], "verification": [ "Recover from the previous complete set.", "Reject an inconsistent mix of database and object generations." ], "deliverables": [ "Backup fallback rehearsal." ], "rollout": "Keep multiple complete generations until retention review permits removal.", "skills": [ "Disaster recovery" ], "fieldMix": [ { "field": "Site reliability", "percentage": 70 }, { "field": "Storage systems", "percentage": 30 } ], "patterns": [] }, { "id": "bc1bb4d9-e9be-4a38-8437-2428fe1928b8", "key": "BRESTORE-110", "title": "Write a restore handoff with promotion and abandonment criteria", "type": "CHORE", "priority": "LOW", "difficulty": "FOUNDATIONAL", "estimateMinutes": 60, "phaseId": "prove", "dependsOn": [ "BRESTORE-109" ], "scenario": "An operator needs to decide whether a long-running restore is safe to promote.", "acceptanceCriteria": [ "List required integrity and compatibility checks.", "Document promotion authority and target identity.", "Explain how to abandon the scratch restore safely." ], "implementationNotes": [ "Avoid destructive cleanup commands outside the named scratch directory." ], "verification": [ "Follow the handoff to promote a valid fixture.", "Keep a restore with missing objects unpromoted." ], "deliverables": [ "Restore runbook." ], "rollout": "Store the runbook with backup manifests and compatible build references.", "skills": [ "Runbooks" ], "fieldMix": [ { "field": "Site reliability", "percentage": 100 } ], "patterns": [] } ] } ] }