{ "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": "ad213ad0-6963-4653-8f19-f91db05f6240", "key": "CLIVE", "title": "A live incident board with recoverable updates", "field": "Real-time systems", "summary": "Keep a synthetic service-status board ordered and replayable over server-sent events.", "context": "Fictional internal status team Harbor updates operational incident cards. Build a local event log and SSE adapter; incidents and service names are invented.", "stack": [ "TypeScript", "Server-sent events", "PostgreSQL adapter", "React" ], "prerequisites": [ "Create synthetic incident revisions and a local append-only event stub.", "Provide controllable disconnect, replay and retention fixtures." ], "developerValue": "Practice event projection, replay and freshness communication.", "companyValue": "Inspect whether dashboards remain trustworthy through network interruptions.", "delivery": "Use local fixtures; this board is not an emergency-response system.", "phases": [ { "id": "events", "title": "Specify live events", "goal": "Define event identity and projection." }, { "id": "replay", "title": "Recover transport gaps", "goal": "Make replay and mutation coherent." }, { "id": "operation", "title": "Operate bounded streams", "goal": "Handle slow clients and explain freshness." } ], "tickets": [ { "id": "7abfb514-9327-4837-98d4-cea65d595f58", "key": "CLIVE-101", "title": "Give live incident events stable opaque identifiers", "type": "TASK", "priority": "MEDIUM", "difficulty": "FOUNDATIONAL", "estimateMinutes": 75, "phaseId": "events", "dependsOn": [], "scenario": "Reconnecting clients cannot distinguish replay from new events because IDs change on delivery. Persist event identity.", "acceptanceCriteria": [ "Replay preserves IDs", "Distinct events have unique IDs", "IDs contain no incident text" ], "implementationNotes": [ "Delivery attempts must not mint new event IDs." ], "verification": [ "Replay one event twice", "Append two equal payloads as distinct events" ], "deliverables": [ "Event identity contract" ], "rollout": "Disable replay until stable IDs exist.", "skills": [ "Event modeling", "Identity" ], "fieldMix": [ { "field": "Real-time systems", "percentage": 60 }, { "field": "Data engineering", "percentage": 40 } ], "patterns": [] }, { "id": "e536906c-fa9c-4c33-9735-51a18e1b8cb7", "key": "CLIVE-102", "title": "Render incident status text independently of severity color", "type": "BUG", "priority": "MEDIUM", "difficulty": "FOUNDATIONAL", "estimateMinutes": 60, "phaseId": "events", "dependsOn": [], "scenario": "Color-only status blocks hide the distinction between investigating and monitoring. Add visible status labels.", "acceptanceCriteria": [ "Every status has text", "Unknown status renders explicit fallback", "Color is optional reinforcement" ], "implementationNotes": [ "Do not infer severity from color tokens." ], "verification": [ "Render all fixture statuses", "Render unsupported status" ], "deliverables": [ "Status presenter and cases" ], "rollout": "Use text-only presentation if color mapping is wrong.", "skills": [ "Accessibility", "State projection" ], "fieldMix": [ { "field": "Accessibility", "percentage": 70 }, { "field": "Frontend", "percentage": 30 } ], "patterns": [] }, { "id": "8f79d82e-e6e3-4c62-bf96-bd3655f0df52", "key": "CLIVE-103", "title": "Apply live incident updates only to newer revisions", "type": "BUG", "priority": "HIGH", "difficulty": "INTERMEDIATE", "estimateMinutes": 120, "phaseId": "events", "dependsOn": [ "CLIVE-101", "CLIVE-102" ], "scenario": "A delayed update reopens a resolved incident. Compare revisions before changing the projected card.", "acceptanceCriteria": [ "Newer revisions apply", "Equal replay is harmless", "Older revisions cannot overwrite" ], "implementationNotes": [ "Revision scope is per incident." ], "verification": [ "Apply revisions in order", "Deliver earlier revision after resolution" ], "deliverables": [ "Revision projector and ordering cases" ], "rollout": "Refresh full cards if ordering cannot be established.", "skills": [ "Ordering", "Idempotency" ], "fieldMix": [ { "field": "Real-time systems", "percentage": 60 }, { "field": "Distributed systems", "percentage": 40 } ], "patterns": [] }, { "id": "541c098e-2239-4661-8393-7c297285f86a", "key": "CLIVE-104", "title": "Resume incident streams from the last applied event", "type": "STORY", "priority": "HIGH", "difficulty": "ADVANCED", "estimateMinutes": 180, "phaseId": "replay", "dependsOn": [ "CLIVE-103" ], "scenario": "A reconnect misses changes made during disconnection. Send the last applied event ID and replay retained updates.", "acceptanceCriteria": [ "Resume begins after acknowledged ID", "Replay preserves event order", "Cursor advances after successful projection" ], "implementationNotes": [ "Received is not equivalent to applied." ], "verification": [ "Reconnect after two missed events", "Fail projection before cursor advancement" ], "deliverables": [ "Resume coordinator and replay cases" ], "rollout": "Force snapshot reload instead of uncertain replay.", "skills": [ "SSE", "Recovery" ], "fieldMix": [ { "field": "Real-time systems", "percentage": 60 }, { "field": "Networking", "percentage": 20 }, { "field": "Distributed systems", "percentage": 20 } ], "patterns": [] }, { "id": "f7a30be4-431c-4735-9245-a14ceb757b4d", "key": "CLIVE-105", "title": "Return a reset contract when incident replay history expired", "type": "TASK", "priority": "HIGH", "difficulty": "INTERMEDIATE", "estimateMinutes": 135, "phaseId": "replay", "dependsOn": [ "CLIVE-104" ], "scenario": "Old clients request a cursor outside retention and appear current with missing changes. Make replay expiry explicit.", "acceptanceCriteria": [ "Expired cursor requests fresh snapshot", "Client clears old cursor", "Reset has an observable reason" ], "implementationNotes": [ "Do not silently start at the newest event." ], "verification": [ "Resume retained cursor", "Resume expired cursor" ], "deliverables": [ "Replay reset contract" ], "rollout": "Require full reload if reset handling fails.", "skills": [ "Protocol design", "Retention" ], "fieldMix": [ { "field": "API design", "percentage": 50 }, { "field": "Real-time systems", "percentage": 30 }, { "field": "Storage systems", "percentage": 20 } ], "patterns": [] }, { "id": "3637e32d-60db-4d8f-8d61-d454a6663ec6", "key": "CLIVE-106", "title": "Join incident snapshots and streams at one watermark", "type": "BUG", "priority": "HIGH", "difficulty": "EXPERT", "estimateMinutes": 240, "phaseId": "replay", "dependsOn": [ "CLIVE-104", "CLIVE-105" ], "scenario": "An update between snapshot fetch and stream connect disappears. Establish a snapshot watermark for replay.", "acceptanceCriteria": [ "Snapshot declares its watermark", "Stream replays later events", "Boundary duplicates remain harmless" ], "implementationNotes": [ "Define transaction or adapter ordering explicitly." ], "verification": [ "Update before snapshot", "Update between snapshot and subscription" ], "deliverables": [ "Snapshot-stream handoff and race cases" ], "rollout": "Use periodic full snapshots while handoff is repaired.", "skills": [ "Consistency", "Transactions" ], "fieldMix": [ { "field": "Distributed systems", "percentage": 50 }, { "field": "Real-time systems", "percentage": 30 }, { "field": "Database engineering", "percentage": 20 } ], "patterns": [] }, { "id": "4edd6f7a-4180-42e3-b999-afb767820cf3", "key": "CLIVE-107", "title": "Reconcile local incident edits with streamed acknowledgements", "type": "STORY", "priority": "MEDIUM", "difficulty": "ADVANCED", "estimateMinutes": 180, "phaseId": "replay", "dependsOn": [ "CLIVE-103", "CLIVE-106" ], "scenario": "Saving an incident and receiving its stream event produces duplicate activity rows. Correlate the committed operation.", "acceptanceCriteria": [ "One committed activity row appears", "Rejected edits remain actionable", "Unrelated remote events still apply" ], "implementationNotes": [ "Do not suppress all events while saving." ], "verification": [ "Save and receive acknowledgement", "Reject save while another user updates" ], "deliverables": [ "Mutation-stream reconciliation" ], "rollout": "Remove optimistic activity until correlation is correct.", "skills": [ "Optimistic UI", "Concurrency" ], "fieldMix": [ { "field": "Frontend", "percentage": 60 }, { "field": "Real-time systems", "percentage": 40 } ], "patterns": [] }, { "id": "6c9c7000-5466-450a-8df9-8c6a6ce3b6e0", "key": "CLIVE-108", "title": "Bound each incident subscriber buffer", "type": "TASK", "priority": "MEDIUM", "difficulty": "ADVANCED", "estimateMinutes": 180, "phaseId": "operation", "dependsOn": [ "CLIVE-106" ], "scenario": "A slow status screen accumulates unbounded events. Cap its queue and require reset when it cannot keep up.", "acceptanceCriteria": [ "Queue respects configured bound", "Overflow terminates with reset guidance", "Other subscribers remain independent" ], "implementationNotes": [ "Never silently discard ordered events." ], "verification": [ "Stream to healthy client", "Stall client beyond queue capacity" ], "deliverables": [ "Subscriber backpressure policy" ], "rollout": "Disconnect slow subscribers and require fresh snapshots.", "skills": [ "Backpressure", "Resource management" ], "fieldMix": [ { "field": "Performance engineering", "percentage": 50 }, { "field": "Real-time systems", "percentage": 30 }, { "field": "Site reliability", "percentage": 20 } ], "patterns": [] }, { "id": "6ef0cabd-cc06-41fa-bda9-6b745b5d9a5b", "key": "CLIVE-109", "title": "Show incident-board freshness independently from incident status", "type": "STORY", "priority": "MEDIUM", "difficulty": "INTERMEDIATE", "estimateMinutes": 105, "phaseId": "operation", "dependsOn": [ "CLIVE-105", "CLIVE-108" ], "scenario": "A disconnected screen says All systems normal because incident cards retain their last values. Add transport freshness.", "acceptanceCriteria": [ "Last applied time is visible", "Disconnect shows stale state", "Reconnect clears stale only after catch-up" ], "implementationNotes": [ "Use synthetic clock values in tests." ], "verification": [ "Disconnect resolved board", "Reconnect with missed open incident" ], "deliverables": [ "Freshness banner and recovery cases" ], "rollout": "Hide aggregate healthy claim while freshness is uncertain.", "skills": [ "UX", "Observability" ], "fieldMix": [ { "field": "Frontend", "percentage": 60 }, { "field": "Real-time systems", "percentage": 40 } ], "patterns": [] }, { "id": "a9e99bf2-dc69-462b-85ac-70af174b3fef", "key": "CLIVE-110", "title": "Record incident-stream recovery reasons without payload logging", "type": "CHORE", "priority": "LOW", "difficulty": "INTERMEDIATE", "estimateMinutes": 90, "phaseId": "operation", "dependsOn": [ "CLIVE-109" ], "scenario": "Investigating replay failures currently logs full incident descriptions. Add an allowlisted recovery event schema.", "acceptanceCriteria": [ "Includes reset reason and cursor category", "Omits descriptions and author names", "Malformed IDs are bounded" ], "implementationNotes": [ "Correlation identifiers cannot carry user text." ], "verification": [ "Capture successful resume", "Reject secret-like malformed cursor" ], "deliverables": [ "Recovery diagnostics and exclusion checks" ], "rollout": "Disable stream logging if payload fields appear.", "skills": [ "Logging", "Data minimization" ], "fieldMix": [ { "field": "Privacy engineering", "percentage": 60 }, { "field": "Real-time systems", "percentage": 20 }, { "field": "Site reliability", "percentage": 20 } ], "patterns": [] } ] } ] }