I imagine that you have to use an Event Sourcing architecture because if you use Kafka as a primary datastore you need to add a lot of complexity outside of Kaf

I imagine that you have to use an Event Sourcing architecture because if you use Kafka as a primary datastore you need to add a lot of complexity outside of Kafka to make it usable. For instance, you cannot query Kafka and this is a basic requirement of most data stores. To get queryable data, you could build up state from events in some external component and then query that external component. From what I understand, this building of state from events is an example of an Event Sourcing architecture. I think event sourcing as a primary datastore is a cool idea. Its fun to play with such ideas on small projects and then scale up. The downside is that Kafka is a distributed monster that is hard to run locally (you need multiple docker containers for a basic setup). I'd be very interested to see if anybody else answers your question.