Modular backend architecture
FiftyFive built the backend in Node.js and TypeScript using Express, with a Controller-Service-Repository structure and tsyringe for dependency injection.
- Controller-Service-Repository separation keeps routing, business logic, and data access independently testable.
- tsyringe dependency injection reduces coupling between modules and simplifies swapping implementations.
- TypeScript enforces contract consistency across authentication, listings, community, and matching modules.
- Module boundaries allowed authentication, listings, and community features to be developed in parallel.