Message Queues (SQS, Pub/Sub)

Summary

A buffer between producers and consumers of messages — decoupling services so a slow or temporarily unavailable consumer doesn't block the producer, and enabling reliable, asynchronous processing.

• 1Set up a message queue and practice sending and receiving a message.
• 2Learn the difference between a queue (one consumer per message) and a topic/pub-sub (many consumers per message).
• 3Understand dead-letter queues and why they matter for handling repeatedly failing messages.