{ "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": "a33baed1-8262-4f90-a081-caa0818640ce", "key": "CFRAME", "title": "An emulated device-link framing library", "field": "Embedded and edge", "summary": "Decode bounded byte streams and recover serial-link framing errors in software.", "context": "Fictional environmental-display devices send synthetic noncritical readings to a local gateway. Implement a byte-stream emulator; no physical device, radio, credentials or safety-critical control is involved.", "stack": [ "TypeScript", "Byte-stream emulator", "Vitest" ], "prerequisites": [ "Specify a small frame format with length sequence payload and checksum.", "Generate local byte streams with fragmentation corruption and reconnects." ], "developerValue": "Practice incremental parsing, fixed resource limits and protocol recovery.", "companyValue": "Inspect whether a device adapter survives malformed input without corrupting accepted readings.", "delivery": "All execution uses software fixtures; hardware timing and production readiness are unqualified.", "phases": [ { "id": "format", "title": "Define frame boundaries", "goal": "Validate bytes before interpreting payloads." }, { "id": "stream", "title": "Handle partial transport", "goal": "Recover fragmented and damaged streams." }, { "id": "operation", "title": "Bound receiver behavior", "goal": "Limit work and explain rejected data." } ], "tickets": [ { "id": "0d475c31-e9f7-47d4-9d51-6d04beb09883", "key": "CFRAME-101", "title": "Decode emulated device frame integers with explicit byte order", "type": "TASK", "priority": "MEDIUM", "difficulty": "FOUNDATIONAL", "estimateMinutes": 75, "phaseId": "format", "dependsOn": [], "scenario": "A synthetic device length reads as 512 instead of 2 because endpoints disagree on byte order. Specify and implement the format.", "acceptanceCriteria": [ "Length and sequence use documented order", "Valid boundary values round-trip", "Truncated integer fields fail explicitly" ], "implementationNotes": [ "Use byte fixtures rather than host-native integer casts." ], "verification": [ "Decode known two-byte values", "Provide truncated header" ], "deliverables": [ "Integer codec and format examples" ], "rollout": "Reject frames from unknown format versions.", "skills": [ "Binary protocols", "Encoding" ], "fieldMix": [ { "field": "Embedded and edge", "percentage": 60 }, { "field": "Networking", "percentage": 40 } ], "patterns": [] }, { "id": "3948ecd1-6416-4492-bfd2-b018fe826261", "key": "CFRAME-102", "title": "Reject emulated device frames above the receiver limit", "type": "BUG", "priority": "HIGH", "difficulty": "FOUNDATIONAL", "estimateMinutes": 75, "phaseId": "format", "dependsOn": [ "CFRAME-101" ], "scenario": "An untrusted length prefix causes a large allocation. Validate declared size before reserving payload storage.", "acceptanceCriteria": [ "Supported sizes pass", "Oversized lengths fail before allocation", "Zero-length policy is explicit" ], "implementationNotes": [ "Keep receiver limits independent from sender claims." ], "verification": [ "Decode small fixture", "Declare maximum integer length" ], "deliverables": [ "Frame admission guard and allocation checks" ], "rollout": "Stop reception if bounded allocation cannot be guaranteed.", "skills": [ "Resource limits", "Input validation" ], "fieldMix": [ { "field": "Embedded and edge", "percentage": 50 }, { "field": "Security", "percentage": 30 }, { "field": "Networking", "percentage": 20 } ], "patterns": [] }, { "id": "81f6c912-1c42-43e4-9fcf-ccd3745e48c9", "key": "CFRAME-103", "title": "Verify emulated device frame checksums before dispatch", "type": "TASK", "priority": "HIGH", "difficulty": "INTERMEDIATE", "estimateMinutes": 120, "phaseId": "format", "dependsOn": [ "CFRAME-101", "CFRAME-102" ], "scenario": "Corrupted readings reach the dashboard because checksum failures are warnings only. Gate payload dispatch on verification.", "acceptanceCriteria": [ "Valid frame dispatches once", "Bad checksum dispatches nothing", "Failure records a bounded category" ], "implementationNotes": [ "Checksum detects corruption and does not authenticate senders." ], "verification": [ "Accept valid frame", "Flip payload byte without updating checksum" ], "deliverables": [ "Checksum gate and corruption cases" ], "rollout": "Disable payload dispatch if verification is unavailable.", "skills": [ "Integrity", "Protocol design" ], "fieldMix": [ { "field": "Embedded and edge", "percentage": 60 }, { "field": "Networking", "percentage": 40 } ], "patterns": [] }, { "id": "acaf701b-d7eb-418c-a71a-a0ac9d7fe153", "key": "CFRAME-104", "title": "Assemble fragmented emulated frames across arbitrary read boundaries", "type": "BUG", "priority": "HIGH", "difficulty": "ADVANCED", "estimateMinutes": 180, "phaseId": "stream", "dependsOn": [ "CFRAME-102", "CFRAME-103" ], "scenario": "A single frame split across reads is discarded as malformed. Maintain incremental parser state.", "acceptanceCriteria": [ "Every legal split yields same frame", "Multiple frames in one read decode", "Incomplete suffix remains bounded" ], "implementationNotes": [ "Transport read boundaries are not message boundaries." ], "verification": [ "Test every split of small frame", "Feed partial header then disconnect" ], "deliverables": [ "Streaming decoder and split cases" ], "rollout": "Buffer only up to the declared frame limit.", "skills": [ "Streaming", "State machines" ], "fieldMix": [ { "field": "Embedded and edge", "percentage": 50 }, { "field": "Networking", "percentage": 50 } ], "patterns": [] }, { "id": "e2e2ebe1-be3f-478f-b33c-67563411344f", "key": "CFRAME-105", "title": "Resynchronize emulated device framing after a corrupt header", "type": "STORY", "priority": "MEDIUM", "difficulty": "ADVANCED", "estimateMinutes": 180, "phaseId": "stream", "dependsOn": [ "CFRAME-104" ], "scenario": "One damaged length prevents decoding all later frames. Recover at a documented sync marker without trusting random payload bytes.", "acceptanceCriteria": [ "Valid later frame can recover", "Recovery scans within a cap", "Rejected bytes never dispatch as readings" ], "implementationNotes": [ "Define marker escaping or ambiguity handling explicitly." ], "verification": [ "Corrupt header before valid frame", "Embed marker-like bytes in payload" ], "deliverables": [ "Resynchronization algorithm and ambiguity cases" ], "rollout": "Close the link when a safe boundary cannot be found.", "skills": [ "Parser recovery", "Protocols" ], "fieldMix": [ { "field": "Embedded and edge", "percentage": 50 }, { "field": "Networking", "percentage": 50 } ], "patterns": [] }, { "id": "b389bc08-6085-4697-a5b7-7f35c28290d1", "key": "CFRAME-106", "title": "Discard incomplete emulated frames after an idle deadline", "type": "TASK", "priority": "MEDIUM", "difficulty": "INTERMEDIATE", "estimateMinutes": 120, "phaseId": "stream", "dependsOn": [ "CFRAME-104", "CFRAME-105" ], "scenario": "A sender transmits a header and stops, pinning a receive buffer indefinitely. Add an injected idle timer.", "acceptanceCriteria": [ "Active progress refreshes deadline", "Expired partial frame releases buffer", "New valid frame can start afterward" ], "implementationNotes": [ "Use monotonic elapsed time rather than calendar time." ], "verification": [ "Complete frame before deadline", "Pause midway beyond deadline" ], "deliverables": [ "Partial-frame timeout and clock cases" ], "rollout": "Reset connection on timeout if local recovery is uncertain.", "skills": [ "Timers", "Resource management" ], "fieldMix": [ { "field": "Embedded and edge", "percentage": 60 }, { "field": "Networking", "percentage": 40 } ], "patterns": [] }, { "id": "ab4382e3-5fbc-48f0-917b-3fdb50f99d4a", "key": "CFRAME-107", "title": "Handle emulated device sequence wrap without accepting stale frames", "type": "BUG", "priority": "HIGH", "difficulty": "EXPERT", "estimateMinutes": 240, "phaseId": "stream", "dependsOn": [ "CFRAME-103", "CFRAME-106" ], "scenario": "Sequence 0 after 65535 is rejected as old, while delayed frames sometimes overwrite current readings. Define a bounded modular-order window.", "acceptanceCriteria": [ "Legitimate wrap is accepted", "Duplicates do not dispatch twice", "Outside-window frames are rejected or require reset" ], "implementationNotes": [ "State the maximum reorder window and session boundary." ], "verification": [ "Feed wrap boundary sequence", "Replay delayed pre-wrap frame" ], "deliverables": [ "Sequence policy and boundary cases" ], "rollout": "Require a new session when sequence ordering is ambiguous.", "skills": [ "Sequence arithmetic", "Ordering" ], "fieldMix": [ { "field": "Embedded and edge", "percentage": 50 }, { "field": "Networking", "percentage": 30 }, { "field": "Distributed systems", "percentage": 20 } ], "patterns": [] }, { "id": "854f60d7-7363-4a5a-b62e-9d2274fc32b9", "key": "CFRAME-108", "title": "Apply backpressure when emulated device consumers fall behind", "type": "TASK", "priority": "HIGH", "difficulty": "ADVANCED", "estimateMinutes": 180, "phaseId": "operation", "dependsOn": [ "CFRAME-104", "CFRAME-107" ], "scenario": "Parsing outruns downstream processing and queues grow indefinitely. Bound accepted-frame buffering.", "acceptanceCriteria": [ "Queue capacity is explicit", "Overflow follows documented reject or pause policy", "Parser state remains valid" ], "implementationNotes": [ "Do not claim lossless delivery under an explicit drop policy." ], "verification": [ "Consume at normal speed", "Stall consumer past capacity" ], "deliverables": [ "Bounded queue and overload cases" ], "rollout": "Pause emulator input if the consumer cannot keep up.", "skills": [ "Backpressure", "Resource limits" ], "fieldMix": [ { "field": "Embedded and edge", "percentage": 40 }, { "field": "Performance engineering", "percentage": 40 }, { "field": "Networking", "percentage": 20 } ], "patterns": [] }, { "id": "0501efec-16f0-4b37-aa1d-d7bc81f78ecf", "key": "CFRAME-109", "title": "Reset emulated receiver state on a new link session", "type": "BUG", "priority": "MEDIUM", "difficulty": "INTERMEDIATE", "estimateMinutes": 105, "phaseId": "operation", "dependsOn": [ "CFRAME-106", "CFRAME-107" ], "scenario": "Bytes from a previous connection combine with a new header after reconnect. Clear session-owned parsing state.", "acceptanceCriteria": [ "New session discards partial buffer", "Sequence window resets by contract", "Completed prior frames remain recorded" ], "implementationNotes": [ "Connection identity must not come from payload text alone." ], "verification": [ "Reconnect after complete frame", "Reconnect mid-header" ], "deliverables": [ "Session reset and reconnect cases" ], "rollout": "Recreate the receiver per connection until state isolation is repaired.", "skills": [ "Lifecycle", "State isolation" ], "fieldMix": [ { "field": "Embedded and edge", "percentage": 60 }, { "field": "Networking", "percentage": 40 } ], "patterns": [] }, { "id": "43f7d910-f089-4148-993b-cf898c3eafef", "key": "CFRAME-110", "title": "Expose emulated frame rejection counters without raw payloads", "type": "CHORE", "priority": "LOW", "difficulty": "INTERMEDIATE", "estimateMinutes": 90, "phaseId": "operation", "dependsOn": [ "CFRAME-108", "CFRAME-109" ], "scenario": "Debug logs contain complete sensor payloads even when only corruption rates are needed. Emit bounded categories.", "acceptanceCriteria": [ "Counts separate size checksum timeout and sequence failures", "Payload bytes are omitted", "Counter reset scope is documented" ], "implementationNotes": [ "Measurements describe the synthetic emulator only." ], "verification": [ "Feed valid and corrupt fixtures", "Inject secret-like payload and inspect logs" ], "deliverables": [ "Receiver metrics contract and samples" ], "rollout": "Disable detailed logging if payload content escapes.", "skills": [ "Observability", "Data minimization" ], "fieldMix": [ { "field": "Embedded and edge", "percentage": 40 }, { "field": "Site reliability", "percentage": 30 }, { "field": "Privacy engineering", "percentage": 30 } ], "patterns": [] } ] } ] }