how Spring event communication is handled? can't see use of ApplicationEventPublisher or EventListener about modulith HOT 1 OPEN

Sorry for the very late reply.

This architecture uses a more functional (as in functional programming) approach to events. That is, the contract for Workflows is to return an event, rather than fire one off to a publisher.

I intentionally avoided the ApplicationEventPublisher because in my experience, use of that makes applications hard to reason about because of the "fire and forget" nature of events. In the long term, issues arise because of the "forget" nature of "fire and forget". As apps become more complex, people "forget" about various events and it becomes a big source of bugs.

If you do want to use ApplicationEventPublisher I suggest you use it for only very narrow uses, for example, like sending an email, if you truly don't care if the email succeeded or not

from modulith.