Amazon SQS
Queue types, visibility timeout, polling, DLQs, and fan-out
Standard vs FIFO Queues
Choose between massive-throughput best-effort (Standard) and ordered exactly-once (FIFO).
Message Lifecycle & Visibility Timeout
Understand how a message is hidden during processing and returned if the consumer fails.
Short vs Long Polling
Cut empty-receive cost and latency by waiting for messages instead of hammering the queue.
Dead-Letter Queues
Isolate messages that repeatedly fail so they stop blocking the queue and can be investigated.
SNS + SQS Fan-out
Broadcast one event to many independent queues by combining a topic with subscriber queues.
Deduplication & Ordering (FIFO)
Get exactly-once processing and strict order out of SQS FIFO using group and dedup ids.
Scaling, Limits & Cost
Know the operational envelope: throughput, message size, retention, and what you pay for.
When to Use SQS
Recognise when a fully-managed cloud queue beats running your own broker.