Redis Streams

Redis Streams is the "I already have Redis, give me Kafka-ish semantics without a new operational dependency" option. Good up to medium throughput, single-region, and short retention. Outgrows the pattern at high throughput / long retention — that's Kafka territory.

The opinion

Use Redis Streams when you already run Redis (you almost certainly do) and you need pub/sub-with-history + consumer groups, but don't yet justify Kafka's operational cost. Cap streams with MAXLEN. Use consumer groups with manual acknowledgement. Periodically claim entries idle for > N minutes (PEL handling). Plan to migrate to Kafka if throughput exceeds ~10k events/sec sustained or you need cross-region replication.

Why Redis Streams over plain pub/sub