Event-Driven Architecture
System design where components communicate through asynchronous events.
Definition
Event-driven architecture is a system design pattern where components communicate through the production and consumption of asynchronous events rather than direct calls. Events represent something that happened; interested components react to events relevant to them.
This approach creates loose coupling, as producers don't need to know about consumers. It enables scalability, resilience, and flexibility in evolving systems independently.
Why It Matters
Tight coupling between services creates fragile systems that are hard to change. Event-driven architecture enables independent scaling, development, and deployment of system components.
For architects, event-driven patterns are essential for building systems that can evolve and scale.
Examples in Practice
An "order placed" event triggers inventory update, payment processing, and email notification independently.
Adding a new analytics consumer requires no changes to existing event producers or consumers.
Event-driven architecture enables replaying events to rebuild state or recover from failures.