Python Microservices Kit: Microservices Patterns Guide

Microservices Patterns Guide A reference for the architectural patterns used in this kit and when to apply them in production. 1. API Gateway What : A single entry point that routes requests to downstream services and handles cross-cutting concerns (auth, rate limiting, logging). When to use : Always. Even with two services, a gateway simplifies client integration and centralises security enforcement. Client → API Gateway → User Service → Order Service Trade-offs : Pro: Single TLS termination point, centralised auth Con: Single point of failure (mitigate with replicas and health checks) 2. Database per Service What : Each microservice owns its data store. Services never access another service's database directly. When to use : Default choice. Sharing a database couples services at the schema level, defeating the purpose of microservices. Implementation : # user-service owns its own SQLite / Postgres DATABASE_URL = sqlite : /// . / users . db # order-service has its own store DATABASE_U