Run and triage Python quality gates with minimal, root-cause fixes; use when validating feature work before completion.
Apply project testing standards for app/tests layout, naming, dependency overrides, and route/service coverage.
Apply typed FastAPI route patterns with clean dependency boundaries, stable error mapping, and test coverage for success/failure paths.
Author review-ready implementation plans grounded in real code, with a hard single-PR size gate and decomposition into safe incremental tasks when exceeded.
Apply partitioned settings and singleton provider patterns; use when adding or refactoring settings and provider wiring.
Operate Backlog.md tasks through the backlog CLI only; use when reading, planning, executing, or finalizing any task under backlog/tasks.
Apply pluggy registration and lifespan startup patterns for package discovery, initialization ordering, and testable startup behavior.
Choose correct Python type boundaries (Protocol, dataclass, BaseModel, TypedDict) for maintainable FastAPI architecture.