fsharp-backend

A layered backend architecture separates concerns into Validation, Domain, Persistence, and API layers. This approach isolates pure business logic from I/O operations, making code testable and deterministic. F# with Giraffe and Fable.Remoting scaffolds these layers automatically under src/Server.

Use Giraffe and Fable.Remoting to define endpoints that enforce validation at the API boundary. The Skill scaffolds Validation.fs to handle input checks before passing data to pure domain logic, preventing invalid state from entering your application.

Yes. The layered architecture enforces I/O separation by keeping domain logic pure and isolated in Domain.fs, while Persistence.fs handles all database operations. This prevents I/O leaks and ensures your business rules remain testable without database dependencies.

Organize your src/Server directory with modules for Validation.fs, Domain.fs, Persistence.fs, and Api.fs. This clean separation ensures validation runs first, domain logic stays pure, persistence handles data access, and API endpoints orchestrate the flow safely.

Yes. Giraffe handles HTTP routing and request processing while Fable.Remoting provides type-safe communication. Together they enable robust, structured API development with automatic scaffolding for endpoints under the layered architecture.

Pure domain logic is deterministic, testable, and free of side effects. Separating it into Domain.fs prevents database or network calls from corrupting business rules, making bugs easier to isolate and tests faster to run without external dependencies.