# Kafka Stream Lineage End to End

Every change to Kafka is a change to something you can't see. Stream Lineage builds the missing dependency map from three things you already have: the ACLs on your cluster, your ownership model, and live traffic through the Gateway.

This walkthrough uses an airline estate to do the three jobs that map unlocks, retiring a topic, tracing a hot path, and turning up a consumer nobody registered.

## What You'll Learn

- How lineage is assembled from ACLs, ownership, and live Gateway traffic
- Confirm a topic is safe to retire before you touch it
- Trace a hot path back to the applications driving it
- Find consumers reading production data outside your ownership model