Your webhook processor receives 10,000 events/second. Your database can handle 500 inserts/second. Without backpressure, your queue grows unbounded, memory fills up, the process crashes, and you lose all the unprocessed events in memory.
Web Streams (WHATWG standard) are now built into Node 18+. Learn when to use ReadableStream vs node:stream, streaming LLM responses, and backpressure handling.
Redis Streams offer persistence, consumer groups, and ordering without Kafka''s operational burden. Perfect for real-time activity feeds and notifications at scale.