{ "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": "a344edd4-0f2f-4cdb-af59-b7bd3bbc5c06", "key": "BENV", "title": "Ephemeral review-environment lifecycle", "field": "Cloud infrastructure", "summary": "Manage short-lived review environments with bounded resources and safe cleanup.", "context": "A fictional product team creates preview environments for pull requests. Forgotten environments accumulate cost, and shared test data leaks between reviews.", "stack": [ "TypeScript", "PostgreSQL", "Infrastructure plan fixtures" ], "prerequisites": [ "Author a local environment-provider double and synthetic pull-request events; provision no external resources." ], "developerValue": "Practice resource lifecycle state machines, isolation, and reconciliation.", "companyValue": "Make review environments predictable, isolated, and accountable to a budget.", "delivery": "Deliver a local lifecycle controller and cleanup rehearsal using simulated resource records.", "phases": [ { "id": "model", "title": "Model environment ownership", "goal": "Define identity, scope, and resource limits." }, { "id": "manage", "title": "Manage lifecycle", "goal": "Create, update, expire, and reconcile environments." }, { "id": "operate", "title": "Operate within bounds", "goal": "Verify cleanup safety and cost controls." } ], "tickets": [ { "id": "8f4a4b8a-7701-4a3c-a570-e20723f5b5c7", "key": "BENV-101", "title": "Define review-environment identity independently of branch names", "type": "TASK", "priority": "MEDIUM", "difficulty": "FOUNDATIONAL", "estimateMinutes": 60, "phaseId": "model", "dependsOn": [], "scenario": "Renamed branches orphan their original preview resources.", "acceptanceCriteria": [ "Use stable repository and change identities.", "Keep branch names as mutable labels.", "Record owner and expiry explicitly." ], "implementationNotes": [ "Use fictional repositories and no real webhook subscription." ], "verification": [ "Rename a synthetic branch without creating another environment.", "Reject conflicting repository identity reuse." ], "deliverables": [ "Environment identity model." ], "rollout": "Adopt identity recording before resource creation.", "skills": [ "Lifecycle modeling" ], "fieldMix": [ { "field": "Cloud infrastructure", "percentage": 60 }, { "field": "Platform engineering", "percentage": 40 } ], "patterns": [] }, { "id": "05af66d5-b1f7-4b0d-a54b-5ad2e8bb5360", "key": "BENV-102", "title": "Set per-environment and per-team resource ceilings", "type": "TASK", "priority": "HIGH", "difficulty": "INTERMEDIATE", "estimateMinutes": 120, "phaseId": "model", "dependsOn": [ "BENV-101" ], "scenario": "One team opens enough previews to exhaust the shared database quota.", "acceptanceCriteria": [ "Declare resource units and budget limits.", "Reserve capacity before creation.", "Reject requests exceeding either ceiling." ], "implementationNotes": [ "Provider resources are simulated records." ], "verification": [ "Reserve an allowed preview.", "Race requests at the limit and prevent over-allocation." ], "deliverables": [ "Quota reservation logic." ], "rollout": "Start with low fixture quotas; release reservations only through terminal lifecycle actions.", "skills": [ "Quota management" ], "fieldMix": [ { "field": "Cloud infrastructure", "percentage": 70 }, { "field": "Platform engineering", "percentage": 30 } ], "patterns": [] }, { "id": "9ef38c04-c504-49da-8fb2-6d3697fd9c89", "key": "BENV-103", "title": "Create environments through idempotent provider operations", "type": "TASK", "priority": "HIGH", "difficulty": "ADVANCED", "estimateMinutes": 180, "phaseId": "manage", "dependsOn": [ "BENV-102" ], "scenario": "A create timeout produces two environments for the same review.", "acceptanceCriteria": [ "Persist a stable operation identity before dispatch.", "Adopt matching provider resources after retry.", "Reject conflicting provider ownership metadata." ], "implementationNotes": [ "Use explicit provider interfaces and local doubles." ], "verification": [ "Recover after an accepted create loses its response.", "Detect an existing resource owned by another review." ], "deliverables": [ "Idempotent provision coordinator." ], "rollout": "Keep uncertain creates pending until reconciliation.", "skills": [ "Provider design", "Idempotency" ], "fieldMix": [ { "field": "Cloud infrastructure", "percentage": 50 }, { "field": "Distributed systems", "percentage": 50 } ], "patterns": [] }, { "id": "f3d0b347-fc66-43fc-8fac-c9c79615a4c9", "key": "BENV-104", "title": "Seed synthetic review data in isolated namespaces", "type": "TASK", "priority": "HIGH", "difficulty": "INTERMEDIATE", "estimateMinutes": 150, "phaseId": "manage", "dependsOn": [ "BENV-103" ], "scenario": "Two previews share account records and interfere with each other's review.", "acceptanceCriteria": [ "Assign a unique data namespace per environment.", "Seed only synthetic records.", "Deny reads across environment namespaces." ], "implementationNotes": [ "Never copy production user data into previews." ], "verification": [ "Run two previews with identical synthetic usernames.", "Verify cross-environment reads and cleanup are denied." ], "deliverables": [ "Isolated seed workflow." ], "rollout": "Validate isolation before marking environments ready.", "skills": [ "Data isolation" ], "fieldMix": [ { "field": "Security", "percentage": 50 }, { "field": "Cloud infrastructure", "percentage": 30 }, { "field": "Database engineering", "percentage": 20 } ], "patterns": [] }, { "id": "8c93b4a3-553b-4f62-bbd5-e9db303976f6", "key": "BENV-105", "title": "Bind preview URLs and callbacks to the environment origin", "type": "BUG", "priority": "HIGH", "difficulty": "ADVANCED", "estimateMinutes": 180, "phaseId": "manage", "dependsOn": [ "BENV-104" ], "scenario": "A preview callback redirects to an unrelated origin supplied in change metadata.", "acceptanceCriteria": [ "Derive allowed origins from trusted environment state.", "Reject arbitrary redirect and callback destinations.", "Expire origin authority when the environment closes." ], "implementationNotes": [ "Use local URLs and do not contact external hosts." ], "verification": [ "Accept the environment's declared local callback.", "Reject a substituted external origin and stale environment." ], "deliverables": [ "Origin binding guard." ], "rollout": "Expose preview links only after origin validation.", "skills": [ "Origin security" ], "fieldMix": [ { "field": "Security", "percentage": 70 }, { "field": "Cloud infrastructure", "percentage": 30 } ], "patterns": [] }, { "id": "df0fb766-4b33-4217-923a-3bba77eb0adc", "key": "BENV-106", "title": "Expire environments using leases rather than event delivery alone", "type": "TASK", "priority": "HIGH", "difficulty": "ADVANCED", "estimateMinutes": 180, "phaseId": "manage", "dependsOn": [ "BENV-103", "BENV-105" ], "scenario": "A missed close event leaves a preview running indefinitely.", "acceptanceCriteria": [ "Persist expiry and extension revisions.", "Reclaim expired environments through a periodic scan.", "Reject stale extensions after cleanup starts." ], "implementationNotes": [ "Lifecycle state changes use explicit transitions." ], "verification": [ "Expire an environment with no close event.", "Race extension and cleanup without resurrecting deleted state." ], "deliverables": [ "Lease-based expiry." ], "rollout": "Start with dry-run expiry reports; enable cleanup after ownership checks.", "skills": [ "Leases", "State machines" ], "fieldMix": [ { "field": "Cloud infrastructure", "percentage": 50 }, { "field": "Distributed systems", "percentage": 30 }, { "field": "Platform engineering", "percentage": 20 } ], "patterns": [] }, { "id": "ed58fe64-6b0b-46c8-8743-c89b46d984fe", "key": "BENV-107", "title": "Reconcile partially created environments after provider failure", "type": "BUG", "priority": "HIGH", "difficulty": "ADVANCED", "estimateMinutes": 210, "phaseId": "manage", "dependsOn": [ "BENV-103", "BENV-106" ], "scenario": "The database resource exists but the web resource failed, leaving an unusable partial preview.", "acceptanceCriteria": [ "Record each provider resource identity.", "Resume or compensate according to lifecycle policy.", "Release quota only after owned resources are accounted for." ], "implementationNotes": [ "Never delete resources without matching ownership metadata." ], "verification": [ "Recover a partially created preview.", "Encounter a foreign resource and stop compensation safely." ], "deliverables": [ "Partial-creation reconciler." ], "rollout": "Keep the environment unavailable until complete; retain reconciliation history.", "skills": [ "Reconciliation", "Recovery" ], "fieldMix": [ { "field": "Cloud infrastructure", "percentage": 50 }, { "field": "Distributed systems", "percentage": 30 }, { "field": "Site reliability", "percentage": 20 } ], "patterns": [] }, { "id": "f59f1c83-434d-4969-8aa3-02964b604ad1", "key": "BENV-108", "title": "Produce a cleanup plan that proves exact resource ownership", "type": "TASK", "priority": "HIGH", "difficulty": "INTERMEDIATE", "estimateMinutes": 150, "phaseId": "operate", "dependsOn": [ "BENV-107" ], "scenario": "A broad name-prefix cleanup could delete another team's preview.", "acceptanceCriteria": [ "List exact resource IDs and ownership bindings.", "Bind deletion intent to lifecycle revision.", "Reject changed ownership or active lease." ], "implementationNotes": [ "Cleanup applies only to the local provider double." ], "verification": [ "Delete an expired owned environment.", "Reject a foreign or newly extended resource." ], "deliverables": [ "Reviewed cleanup plan." ], "rollout": "Use dry-run output first; stop on any ownership mismatch.", "skills": [ "Resource safety" ], "fieldMix": [ { "field": "Security", "percentage": 50 }, { "field": "Cloud infrastructure", "percentage": 50 } ], "patterns": [] }, { "id": "858dae45-ee39-471e-bc3f-36446294374e", "key": "BENV-109", "title": "Compare pooled and dedicated preview dependencies", "type": "TASK", "priority": "HIGH", "difficulty": "EXPERT", "estimateMinutes": 300, "phaseId": "operate", "dependsOn": [ "BENV-104", "BENV-108" ], "scenario": "Dedicated databases simplify isolation but cost more than a shared instance with namespaces.", "acceptanceCriteria": [ "Compare isolation, startup time, cleanup, and quota assumptions.", "Rehearse cross-environment denial for the pooled option.", "Document failure domains and untested provider behavior." ], "implementationNotes": [ "No speculative infrastructure is required beyond the local model." ], "verification": [ "Evaluate both options against the same synthetic review workload.", "Reject a cheaper option that fails isolation requirements." ], "deliverables": [ "Preview architecture decision record." ], "rollout": "Choose the smallest option satisfying isolation; keep migration and cleanup steps explicit.", "skills": [ "Cloud architecture", "Tradeoff analysis" ], "fieldMix": [ { "field": "System design", "percentage": 40 }, { "field": "Cloud infrastructure", "percentage": 40 }, { "field": "Security", "percentage": 20 } ], "patterns": [] }, { "id": "309e2052-80cb-4951-babd-6ae160a1eccd", "key": "BENV-110", "title": "Write a stale-preview support checklist", "type": "CHORE", "priority": "LOW", "difficulty": "FOUNDATIONAL", "estimateMinutes": 60, "phaseId": "operate", "dependsOn": [ "BENV-109" ], "scenario": "Reviewers need to know whether a broken preview is creating, expired, or awaiting cleanup.", "acceptanceCriteria": [ "Expose lifecycle state and last safe failure category.", "Show owner, expiry, and review identity.", "Document scoped retry and extension behavior." ], "implementationNotes": [ "Status contains no credentials or seed data." ], "verification": [ "Diagnose an expired synthetic preview.", "Reject extension after irreversible cleanup begins." ], "deliverables": [ "Preview support guide." ], "rollout": "Ship with lifecycle controls and update after state changes.", "skills": [ "Operational UX" ], "fieldMix": [ { "field": "Frontend", "percentage": 40 }, { "field": "Cloud infrastructure", "percentage": 30 }, { "field": "Site reliability", "percentage": 30 } ], "patterns": [] } ] } ] }