event-driven-architecture

Event-driven architecture is an asynchronous pattern that decouples microservices via event streams to improve resilience and enable scalable data flows. You need it when building distributed domains requiring reliable, independent service communication and immutable history.

Choosing a messaging backbone requires evaluating throughput, ordering, and routing needs across distributed systems. This guidance specifies tooling recommendations for Kafka, RabbitMQ, and SQS/SNS to match your specific event-driven scalability and reliability requirements.

Implement CQRS and event sourcing by mapping services to event streams and setting up an event store for immutable history. This separates write models from scalable read models, enabling reliable replayability and robust data consistency across distributed domains.

The best way to handle data consistency in event-driven systems is applying sagas for reliable distributed transactions and configuring idempotency with retries. This guidance specifies error handling and governance requirements to ensure robust messaging and prevent data loss.

Event-driven architecture supports schema evolution by applying governance requirements and best-practice patterns for asynchronous messaging. This ensures robust distributed systems can evolve message contracts without breaking existing event streams or decoupled microservices.

You should not use event sourcing and CQRS when your backend architecture requires simple synchronous transactions without replayability needs. If distributed data flows and scalable read/write separation are unnecessary, the added complexity of event-driven patterns outweighs their benefits.