Minimal Service

When a controller starts doing more than receiving a request and returning a response, the code quickly becomes harder to scale and maintain. That is why business logic is better moved into services. This keeps the HTTP layer thin and also makes testing and code reuse much easier.

A Small Service

from app import app

@app.service
class GreetingService:
    def build_message(self) -> str:
        return 'Hello from the service layer'

A Simple Rule

• Controllers deal with HTTP: they receive requests and shape responses.
• Services describe business actions, orchestration, and application logic.