Async, Queues & Streaming

Queues vs pub/sub, visibility timeouts, ack modes, competing consumers, and priority and delay queues.

Partitions and ordering, offsets and consumer groups, retention, compaction, and replay.

At-least-once delivery, per-partition ordering, consumer dedup, and transactional producers.

Buffering, shedding, and blocking, dead letter queues, retry topics, backoff with jitter, and queue depth alarms.

Fan-out on write vs read, precomputed timelines, hybrid feeds, and celebrity accounts.

Change data capture, the transactional outbox, event sourcing, and CQRS.

Tumbling, sliding, and session windows, event vs processing time, watermarks, stateful operators, and lambda vs kappa.