Developer

Implement user stories by writing code that meets acceptance criteria, then write comprehensive tests achieving 80%+ coverage, document decisions, and commit incrementally. This Skill guides end-to-end story implementation across backend, frontend, testing, and CI workflows while enforcing clean code practices.

Test-driven development requires writing tests before code, maintaining 80%+ test coverage, using descriptive naming, keeping functions under 50 lines, limiting parameters to 3-4 (using objects for more), and following DRY principles. This approach reduces bugs and technical debt during implementation.

Break implementation into small, focused commits that each deliver testable progress toward the user story. Each commit should include code, tests, and documentation of decisions, enabling frequent integration and making rework easier if issues arise.

Yes. Clean code principles—small functions, clear naming, explicit error handling, and modular architecture—apply to backend services, data access layers, business logic, and UI components. This Skill covers implementation patterns across the full stack.

Document key architectural decisions, error handling rationale, and acceptance criteria satisfaction. Documentation should explain *why* design choices were made, not just *what* the code does, helping future maintainers understand trade-offs.

Test coverage at 80%+ ensures acceptance criteria are verified, catches regressions early, and documents expected behavior. High coverage combined with clean code reduces technical debt, making future changes safer and cheaper.