Haskell Web Service (Haskell, Servant, PostgreSQL, Docker, Nix) overview

A strongly-typed web service built with Haskell and the Servant library, which derives API documentation and client code from type-level route definitions. PostgreSQL handles persistence via persistent or raw SQL, while Aeson manages JSON serialization with compile-time guarantees. Nix provides reproducible builds and dependency management, eliminating "works on my machine" issues across development and CI environments. Docker packages the final binary into minimal containers. The tradeoff is a steep learning curve around monad transformers and type-level programming, but the payoff is exceptionally reliable, refactor-friendly service code.