{ "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": "ceb5bcc9-8949-4987-a0cb-1ceeca794793", "key": "AMERGE", "title": "Synchronize offline equipment inspections without silent overwrites", "field": "Distributed systems", "summary": "Merge local inspection changes with explicit conflicts, tombstones and attachment identity.", "context": "A fictional field team inspects equipment with intermittent connectivity. Two tablets can edit the same checklist and an old upload may restore a deleted finding.", "stack": [ "TypeScript", "PostgreSQL", "HTTP" ], "prerequisites": [ "Create two local client-state simulators and a synthetic inspection API.", "Use fabricated notes and local attachment bytes." ], "developerValue": "Practice offline synchronization, causal revisions and conflict resolution.", "companyValue": "Review whether field work survives disconnection without hiding conflicting observations.", "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": "changes", "title": "Define change identities", "goal": "Represent offline edits and authority boundaries." }, { "id": "merge", "title": "Synchronize and resolve", "goal": "Handle duplicates, conflicts and deletion safely." }, { "id": "recovery", "title": "Recover interrupted synchronization", "goal": "Reconcile attachments and explain remaining conflicts." } ], "tickets": [ { "id": "00b9f2de-8655-4909-813d-3e20e4d273fb", "key": "AMERGE-101", "title": "Define offline change envelopes with stable client operation IDs", "type": "TASK", "priority": "MEDIUM", "difficulty": "FOUNDATIONAL", "estimateMinutes": 90, "phaseId": "changes", "dependsOn": [], "scenario": "A tablet retries saved edits with new request IDs, so the server creates duplicate inspection findings.", "acceptanceCriteria": [ "Include operation ID, inspection ID, base revision and change type.", "Keep device display name separate from identity.", "Reject unknown envelope versions before mutation." ], "implementationNotes": [ "Use generated disposable client identities." ], "verification": [ "Replay the same synthetic change envelope twice.", "Change content under the same operation ID and return conflict." ], "deliverables": [ "Offline operation contract" ], "rollout": "Publish the envelope before enabling sync retries; keep incompatible operations in local pending state.", "skills": [ "Protocol design", "Idempotency" ], "fieldMix": [ { "field": "Distributed systems", "percentage": 50 }, { "field": "API design", "percentage": 30 }, { "field": "Mobile", "percentage": 20 } ], "patterns": [] }, { "id": "23929c4e-f871-4818-ae90-a87331742194", "key": "AMERGE-102", "title": "Require current inspection access before applying a queued offline change", "type": "TASK", "priority": "HIGH", "difficulty": "INTERMEDIATE", "estimateMinutes": 150, "phaseId": "changes", "dependsOn": [ "AMERGE-101" ], "scenario": "A contractor loses project access while offline, then reconnects with a batch of previously authorized edits.", "acceptanceCriteria": [ "Reauthorize each target at synchronization time.", "Reject revoked or cross-organization changes without partial hidden writes.", "Return safe per-operation outcomes under the declared batch policy." ], "implementationNotes": [ "Offline possession of data is not continuing write authority." ], "verification": [ "Apply a queued edit for a still-authorized actor.", "Revoke access before reconnect and verify no inspection mutation." ], "deliverables": [ "Sync authorization boundary" ], "rollout": "Enable scope checks before bulk sync; retain rejected local operations for user review.", "skills": [ "Authorization", "Offline systems" ], "fieldMix": [ { "field": "Security", "percentage": 50 }, { "field": "Distributed systems", "percentage": 30 }, { "field": "Mobile", "percentage": 20 } ], "patterns": [] }, { "id": "1690b2fe-46a4-4981-9edb-d3c3ff64be86", "key": "AMERGE-103", "title": "Distinguish independent checklist edits from conflicting edits", "type": "TASK", "priority": "MEDIUM", "difficulty": "FOUNDATIONAL", "estimateMinutes": 120, "phaseId": "changes", "dependsOn": [ "AMERGE-101", "AMERGE-102" ], "scenario": "The sync service treats every concurrent change as either a blanket overwrite or a blanket conflict.", "acceptanceCriteria": [ "Define fields that can merge independently.", "Require explicit conflict when the same protected value diverges.", "Document attachment and deletion conflict rules separately." ], "implementationNotes": [ "Use a small fixed checklist; avoid a general-purpose merge language." ], "verification": [ "Merge edits to two independent checklist items.", "Edit the same item differently and preserve both proposed values as a conflict." ], "deliverables": [ "Merge policy table and worked examples" ], "rollout": "Review the policy before automatic merging; keep unresolved fields on manual resolution.", "skills": [ "Conflict modeling", "Data semantics" ], "fieldMix": [ { "field": "Distributed systems", "percentage": 60 }, { "field": "System design", "percentage": 40 } ], "patterns": [] }, { "id": "7acc7ed6-1787-43b0-b380-ae52c52780d9", "key": "AMERGE-104", "title": "Apply offline operations with a durable deduplication record", "type": "STORY", "priority": "MEDIUM", "difficulty": "ADVANCED", "estimateMinutes": 210, "phaseId": "merge", "dependsOn": [ "AMERGE-101", "AMERGE-102", "AMERGE-103" ], "scenario": "The server applies a change, loses the response, then reapplies it after the tablet reconnects.", "acceptanceCriteria": [ "Commit operation identity and inspection mutation atomically.", "Return the original safe outcome for identical retries.", "Keep rejected authorization separate from accepted-operation history." ], "implementationNotes": [ "Scope deduplication to the authorized client and operation identity." ], "verification": [ "Drop the response after commit and retry to one revision.", "Force transaction rollback and verify the operation remains retryable without a partial edit." ], "deliverables": [ "Idempotent sync transaction" ], "rollout": "Canary one synthetic client; pause replay when canonical operation identity is inconsistent.", "skills": [ "Transactions", "Idempotency" ], "fieldMix": [ { "field": "Distributed systems", "percentage": 50 }, { "field": "Database engineering", "percentage": 50 } ], "patterns": [] }, { "id": "06d5245b-f9ce-48fb-a4a4-4151d20ec15a", "key": "AMERGE-105", "title": "Preserve concurrent inspection findings as explicit conflicts", "type": "TASK", "priority": "MEDIUM", "difficulty": "ADVANCED", "estimateMinutes": 240, "phaseId": "merge", "dependsOn": [ "AMERGE-103", "AMERGE-104" ], "scenario": "Two inspectors change a safety finding from different base revisions and last-write-wins hides one observation.", "acceptanceCriteria": [ "Detect divergence from the declared base revision.", "Persist both proposals and their operation identities.", "Block authoritative resolution until a permitted resolution command chooses or combines them." ], "implementationNotes": [ "Do not infer which observer is correct from arrival time." ], "verification": [ "Submit conflicting changes in both arrival orders and retain equivalent conflict facts.", "Attempt ordinary edit completion over an unresolved conflict and reject it." ], "deliverables": [ "Conflict record model and order-invariance tests" ], "rollout": "Enable conflict capture before automatic reconciliation; leave existing ambiguous cases unresolved.", "skills": [ "Conflict detection", "Causal revisions" ], "fieldMix": [ { "field": "Distributed systems", "percentage": 70 }, { "field": "Backend", "percentage": 30 } ], "patterns": [] }, { "id": "46f017a0-c3cc-4216-aa44-ec970be6a010", "key": "AMERGE-106", "title": "Resolve an inspection conflict against its current proposal set", "type": "STORY", "priority": "MEDIUM", "difficulty": "INTERMEDIATE", "estimateMinutes": 180, "phaseId": "merge", "dependsOn": [ "AMERGE-105" ], "scenario": "A reviewer resolves a conflict while a third offline proposal arrives, silently discarding the new observation.", "acceptanceCriteria": [ "Bind resolution to the expected conflict revision and proposal identities.", "Record resolution as an append-only fact.", "Reject stale resolution without deleting proposals." ], "implementationNotes": [ "Require the reviewer's current inspection permission." ], "verification": [ "Resolve an unchanged two-proposal conflict.", "Add a third proposal before commit and verify stale resolution conflicts." ], "deliverables": [ "Guarded conflict resolution command" ], "rollout": "Canary synthetic review; reopen by appending a new conflict fact rather than editing history.", "skills": [ "Optimistic concurrency", "Auditability" ], "fieldMix": [ { "field": "Distributed systems", "percentage": 50 }, { "field": "Database engineering", "percentage": 30 }, { "field": "Backend", "percentage": 20 } ], "patterns": [] }, { "id": "21a45a88-e345-4d3d-b42f-67de25131602", "key": "AMERGE-107", "title": "Keep deleted findings deleted when an old tablet reconnects", "type": "TASK", "priority": "HIGH", "difficulty": "EXPERT", "estimateMinutes": 300, "phaseId": "merge", "dependsOn": [ "AMERGE-103", "AMERGE-104", "AMERGE-105" ], "scenario": "A tablet that missed a deletion resubmits its old finding and recreates content the team intentionally removed.", "acceptanceCriteria": [ "Represent deletion with an ordered tombstone.", "Reject stale recreation under the declared merge policy.", "Define tombstone retention and resnapshot requirements." ], "implementationNotes": [ "Avoid using wall-clock time alone to order deletion and recreation." ], "verification": [ "Delete a finding and replay an older update.", "Expire supported replay history in the simulator and require resnapshot rather than guessing." ], "deliverables": [ "Tombstone protocol and stale-client cases" ], "rollout": "Deploy tombstones before cleanup; halt tombstone removal until the resnapshot contract is available.", "skills": [ "Deletion semantics", "Synchronization" ], "fieldMix": [ { "field": "Distributed systems", "percentage": 60 }, { "field": "Data engineering", "percentage": 40 } ], "patterns": [] }, { "id": "a336a380-c9ae-46ac-9a58-41afc858ed19", "key": "AMERGE-108", "title": "Finalize offline attachments by verified content identity", "type": "TASK", "priority": "MEDIUM", "difficulty": "ADVANCED", "estimateMinutes": 210, "phaseId": "recovery", "dependsOn": [ "AMERGE-104", "AMERGE-107" ], "scenario": "An inspection references a photo before its interrupted upload completes, producing broken evidence links in the field report.", "acceptanceCriteria": [ "Stage attachment uploads separately from finding references.", "Finalize only exact verified object generation and content hash.", "Keep incomplete attachments visible as pending without public links." ], "implementationNotes": [ "Use synthetic images or byte fixtures; no personal photographs are needed." ], "verification": [ "Complete a valid synthetic attachment and resolve its stable identity.", "Interrupt upload or alter bytes and verify the finding cannot publish an invalid link." ], "deliverables": [ "Attachment finalization contract" ], "rollout": "Canary local attachments; keep staged objects private and resume or discard only exact generations.", "skills": [ "Storage integrity", "Offline workflows" ], "fieldMix": [ { "field": "Storage systems", "percentage": 50 }, { "field": "Distributed systems", "percentage": 30 }, { "field": "Mobile", "percentage": 20 } ], "patterns": [] }, { "id": "691ce9a1-3402-42a7-8594-82ca7b16de53", "key": "AMERGE-109", "title": "Resume inspection synchronization from a server-confirmed cursor", "type": "TASK", "priority": "MEDIUM", "difficulty": "EXPERT", "estimateMinutes": 300, "phaseId": "recovery", "dependsOn": [ "AMERGE-104", "AMERGE-106", "AMERGE-107", "AMERGE-108" ], "scenario": "The tablet stores a local cursor before receiving server confirmation and skips updates after a crash.", "acceptanceCriteria": [ "Advance the local acknowledged cursor only after durable server outcome.", "Bind cursor to inspection scope and sync generation.", "Require resnapshot when the server cannot honor the retained history window." ], "implementationNotes": [ "Use two client simulators with controlled interruption points." ], "verification": [ "Crash during a sync page and resume without missing confirmed operations.", "Use an expired or cross-scope cursor and reject incremental sync safely." ], "deliverables": [ "Cursor recovery protocol and crash harness" ], "rollout": "Enable incremental sync after the resnapshot path passes; retain local pending operations until acknowledged.", "skills": [ "Checkpointing", "Recovery" ], "fieldMix": [ { "field": "Distributed systems", "percentage": 60 }, { "field": "Mobile", "percentage": 40 } ], "patterns": [] }, { "id": "aadba700-8c89-4e22-997d-d1a62e845b3d", "key": "AMERGE-110", "title": "Show sync completion separately from resolved inspection conflicts", "type": "TASK", "priority": "MEDIUM", "difficulty": "FOUNDATIONAL", "estimateMinutes": 90, "phaseId": "recovery", "dependsOn": [ "AMERGE-106", "AMERGE-108", "AMERGE-109" ], "scenario": "A tablet says all synced even though uploaded changes contain unresolved conflicts and a pending attachment.", "acceptanceCriteria": [ "Report transport acknowledgement, conflict state and attachment state separately.", "Keep rejected operations visible with safe reasons.", "Never equate uploaded data with an approved inspection." ], "implementationNotes": [ "Use a local status projection with accessible plain-language labels." ], "verification": [ "Display a fully acknowledged conflict-free synthetic inspection.", "Acknowledge a conflicting batch and retain unresolved status." ], "deliverables": [ "Sync status contract and state examples" ], "rollout": "Publish precise status labels; restore prior layout without collapsing distinct states.", "skills": [ "Distributed UX", "State semantics" ], "fieldMix": [ { "field": "Mobile", "percentage": 50 }, { "field": "Distributed systems", "percentage": 50 } ], "patterns": [] } ] } ] }