AWS Event-Driven Messaging: SNS, SQS, EventBridge, and Beyond
Most teams bolt messaging onto their architecture after the first production outage caused by synchronous service-to-service calls. A payment service calls an inventory service directly, the inventory service is slow, the payment service times out, the customer gets charged twice. Suddenly everyone agrees the system needs a queue. I have spent years designing event-driven systems on AWS: order processing pipelines handling millions of transactions per day, IoT telemetry ingestion at hundreds of thousands of events per second, multi-region fan-out architectures coordinating dozens of microservices. AWS offers at least six distinct messaging and eventing services. Each solves a different problem. Choosing wrong means either overengineering a simple notification flow or discovering at 3 AM that your architecture cannot handle the throughput your business requires. This article is not a getting-started guide. It is an architecture reference for engineers who need to pick the right service, configure it correctly, and avoid the failure modes that surface only under production load.