In a proper kafka setting you would use avro and a schema repository to have defined schemas for your events and have an ability to upgrade schemas automaticall

In a proper kafka setting you would use avro and a schema repository to have defined schemas for your events and have an ability to upgrade schemas automatically. For breaking changes you would use kafka streams to migrate the old topic into a new topic and then discard the old topic. Kafka has transactions, and with kafka streams you can create joined views that include those transactions. It’s a different way of working for sure, but for an event sourced system I think kafka is an excellent choice. In a sql database keeping the complete history of changes for years is much less practical than in kafka. What you shouldn’t do is look at kafka as a database. It’s a message log. You push messages in, you eventually read them back out. The key word is eventually. You can’t read your writes, and that makes building an interactive system on top hard.