WebSocket on Steroids, or Kafka with retention.ms=0

Kafka supports a zero-retention topic — retention.ms=0 — and it still works.

You can send messages to such a topic, and Kafka will deliver them to all active consumers. No persistence. No logs. Pure firehose.

This effectively turns Kafka from a log-based broker into a real-time pub/sub system, almost like WebSocket — but with Kafka-grade reliability and scale.

📌 Rarely used, but incredibly useful for:

• transient notifications
• internal event routing
• stateless delivery: "don't store, just stream"