Activity tracking. This was the original use case for Kafka. ...
Real-time data processing. Many systems require data to be processed as soon as it becomes available. ...
Messaging. ...
Operational Metrics/KPIs. ...
Log Aggregation. ...
“Little” Data. ...
Streaming ETL.
https://www.upsolver.com/blog/apache-kafka-use-cases-when-to-use-not