Event-Driven Architecture in Node.js: Patterns That Scale

As your Node.js services grow, synchronous request-response patterns start to show their limits. Event-driven architecture (EDA) offers a path to loosely coupled, highly scalable systems.

Core concepts: - Event Producers: Services that emit events when something happens - Event Consumers: Services that react to events - Event Broker: The middleware that routes events (Redis Streams, RabbitMQ, Kafka)

We'll explore three patterns: 1. Simple Pub/Sub with Redis Streams 2. Event Sourcing for audit trails 3. CQRS for read/write optimization