Amazon EventBridge
EventBridge is an event hub that receives application events on a central bus and routes them to other targets through rules. It creates event-driven flows without requiring producers and consumers to call each other directly.
▶Architecture Diagram
🔗 RelationshipDashed line animations indicate the flow direction of data or requests
If order events, payment completions, and signups are wired as direct service-to-service calls, changing one workflow means touching every connected consumer. Without a central place to classify and route events, coupling rises quickly as the system grows.
Early event systems relied heavily on direct service calls or custom webhook connections, causing complexity to rise quickly. This is why models like EventBridge — collecting events on a central bus and routing them by rules — became important.
EventBridge uses an event bus and rules to route incoming events to matching targets like Lambda, SQS, or Step Functions. It also handles scheduled execution and SaaS event collection.
EventBridge and API Gateway can both sit at the start of a flow, but the input type is different. EventBridge routes events that have already happened through rules asynchronously, while API Gateway receives external requests and applies auth and policy at the front door. If you need to loosely connect internal events, look at EventBridge; if you need to expose an HTTP API to external clients, look at API Gateway.
Well-suited for domain event routing, AWS service event processing, SaaS integration, scheduled execution, and loosely coupled system design. Not a good fit for workflow orchestration requiring multi-step state management, branching, and retries.