SQS vs SNS vs EventBridge: queue, publish or route?

Choose from the required delivery shape

A render job waiting for a worker is a queueing problem. A notification distributed to several subscribed consumers is a publish-and-subscribe problem. An application event routed according to content is an event-routing problem.

A single workflow can contain all three needs. Routing a render event into a queue can separate event selection from worker capacity. The presence of an event bus does not remove the need to handle delivery and processing failures.

Delivery is not successful processing

A consumer must handle duplicates, retries and its own failures according to the selected service configuration. Do not assume exactly-once business side effects merely because transport has a particular ordering or deduplication feature.

For queued workers, visibility timeout, idempotency and dead-letter handling matter. For publishers and routes, inspect supported targets, filtering and failure handling rather than transferring assumptions from another service.

Backpressure reveals why a queue is useful

Change arrivals and worker capacity in the experiment. The backlog grows when demand exceeds completion. The buffer buys time; it does not manufacture downstream capacity.

For a second subscriber, decide whether it needs an independent queue. Independent consumer paths can prevent a slow consumer from being treated as the sole owner of shared work. The model here visualizes one queue and excludes real delivery APIs.

Verify changing limits before choosing

Message limits, quotas and pricing evolve and differ between services. Use current official documentation for the specific API, target and Region. Do not assume one service changed its payload limit because another did.

Write down the required consumers, ordering, failure handling and throughput before comparing costs. A short product-name table cannot replace those constraints.

Sources and scope

Reviewed against these official references. The model’s supported scope appears alongside its controls.

• AWS: SQS overview
• AWS: SNS overview
• AWS: EventBridge overview