> Can you guarantee ordering? Can you guarantee exactly once? How do you get transactional semantics? How do you handle cascading failures? It's all a bit overwhelming.

I don’t advocate DDD/microservices but if you absolutely must go down this road, Kafka Streams really neatly answers all these questions. Ben Stopford’s book[0] and blog posts[1] are really great if you want to know more.

[0] http://www.benstopford.com/2018/04/27/book-designing-event-d...

[1] https://www.confluent.io/blog/building-a-microservices-ecosy...