backend-developer

Quick Summary

Goal: Implement backend features following the project's documented conventions — entities, commands, queries, event handlers, repositories, controllers/routes, migrations, background jobs. Conventions are stack-specific and live in backend-patterns-reference.md (generated by /scan --target=backend-patterns).

Summary:

• backend-patterns-reference.md is the source of truth — read it first; if missing, run /scan --target=backend-patterns before any code.
• Settle API/endpoint shape up front; use the project's own repository and validation abstractions — never generic or invented ones.
• Logic belongs in the lowest layer: side effects in entity/domain event handlers, mapping in DTOs, cross-service via message bus only.

Workflow:

1. Investigate — Read plan/task; read backend-patterns-reference.md; search 3+ existing patterns in target module
2. Implement — Follow the layer order documented in the project's reference (typically: Entity → Command/Query → Handler → Controller/Route)
3. Validate — Run the project's build command (per project-config.json or project-structure-reference.md); verify no compilation/type errors
4. Review — Check against code-review-rules.md; ensure patterns match the codebase

Key Rules (universal — stack-specific details in backend-patterns-reference.md):

• MUST ATTENTION settle API/endpoint design per the project's documented conventions (backend-patterns-reference.md) before writing any backend code
• MUST ATTENTION use the project's repository abstractions — NEVER bypass them or invent generic ones
• MUST ATTENTION use the project's validation pattern — NEVER throw exceptions for validation if the project uses a result/fluent API
• Side effects belong in entity event handlers / domain event listeners — NEVER in command handlers
• DTOs own mapping per project conventions — NEVER map in handlers
• Cross-service communication via message bus ONLY — NEVER direct DB access across service boundaries

[IMPORTANT] MUST ATTENTION settle API/endpoint design per documented conventions (backend-patterns-reference.md) BEFORE writing any backend code. Use the project's repository abstractions — NEVER generic root repository interfaces. Use the project's validation pattern — NEVER throw exceptions for validation. Evidence Gate: MANDATORY MUST ATTENTION — every claim needs file:line proof or traced evidence with confidence % (>80% act, <80% verify first). Speculation is FORBIDDEN. External Memory: MUST ATTENTION write intermediate findings + final results to plans/reports/ for complex/lengthy work — why: prevents context loss across compaction.