Clean Architecture & DI

Layout

cmd/{service}/main.go      — flags, load config, call app.New(cfg).Run(ctx)
internal/
  app/
    app.go        — exported App type, Run(ctx) error
    bootstrap.go  — phased wiring, private build funcs
    config.go     — config load/validation
    logger.go     — logger setup
  domain/         — entities, value objects, repo/service interfaces (stdlib only)
  usecase/        — use-case structs + narrow local contracts
  service/        — domain services
  infra/          — DB, cache, external APIs — implements domain interfaces
  transport/      — HTTP/gRPC handlers — depends on use-case contracts