Application Integration
CoreAmazon SQS
Durable managed message queues for buffering, backpressure, retries, and independent worker scaling.
Key points
- Standard queues provide high scale with at-least-once delivery, so consumers must tolerate duplicates.
- FIFO queues add ordering and deduplication semantics for workloads that truly require them.
- Visibility timeouts, dead-letter queues, queue age, and idempotency are core reliability controls.
Best-known use cases
- Absorb bursts when workers cannot process at producer speed.
- Decouple a request path from unreliable or slow background work.
What candidates often confuse it with
- SQS buffers work; SNS broadcasts messages and EventBridge routes events.
- SQS transports independent tasks; Step Functions models workflow state and branches.
Key takeaway
Choose SQS when durable backlog and backpressure are the decisive requirements.
Related services
- Amazon SNS
- Amazon EventBridge
- AWS Step Functions
- AWS Lambda
Relevant exam tasks
- D2.1
- D3.2