In one sentence
Use SQS to queue work, SNS to fan out notifications, and EventBridge to route structured events by rules.
Key points
- SQS buffers messages for consumers to pull and supports independent retries and DLQs.
- SNS pushes one published message to multiple subscribers.
- EventBridge matches event patterns and sends events to selected targets across AWS, applications, and SaaS.
Exam takeaway
A common design is EventBridge or SNS for routing, with SQS queues protecting individual consumers.
Additional decision dimensions
- SQS is a poll-based queue with backlog for buffering, backpressure, and failure isolation.
- SNS provides immediate push fan-out to multiple subscribers.
- EventBridge routes by event content to multiple targets and supports archive/replay and SaaS integrations.
- A common design is SNS/EventBridge → SQS: routing or fan-out first, then an independent buffer per consumer.