Event-driven architecture (EDA) has become one of the dominant patterns in modern distributed systems design. Its appeal is clear: loosely coupled components communicate asynchronously through events, enabling independent scaling, improved resilience, and real-time responsiveness. But EDA's benefits come with genuine complexity, and applying it where simpler patterns would suffice creates unnecessary challenges.
When EDA Makes Sense
EDA shines in scenarios with naturally asynchronous business processes (order fulfillment, notification delivery), systems requiring fan-out (one event triggering multiple independent consumers), audit and replay requirements (event logs provide a complete record of what happened and enable replay for debugging or reprocessing), and integration scenarios where components should be decoupled from each other's availability.