Express Microservices Architecture

This is a solid foundation for building Express.js microservices with all the patterns you actually need in production. It covers the middleware pipeline architecture, routing strategies, and the core microservices patterns like API Gateway, Circuit Breaker, and Saga for distributed transactions. You'll find practical implementations of error handling middleware, request data sharing between middleware layers, and service discovery approaches. Use this when you're moving beyond basic Express APIs into proper distributed systems, whether you're breaking apart a monolith or building event-driven services from scratch. The CQRS and database-per-service patterns are here too, along with the tradeoffs you'll face around data consistency and distributed transactions.