Vertical Slice Architecture

Quick Reference: The 5 Rules

1. One feature = one directory containing handler, request/response types, validation, and tests
2. One entry point per feature — a setup/registration function that receives the router and dependencies. Name varies by convention (Setup, RegisterRoute, Map); the role is the invariant, not the name.
3. Minimize coupling between slices, maximize coupling within a slice
4. No premature abstractions — no shared repository/service layers until genuine duplication emerges across multiple slices
5. Test each feature primarily through its entry point, verifying outcomes (DB state, API calls, response). Platform/adapter tests are also encouraged.

Project Structure