Message bus solutions are indeed truly powerful; but if you need / want predictable order of execution then they are more difficult (or just (d)evolve into multiple points of serialized behavior).
Not sure they are looking for a message bus solution in this case? I would expect there needing to be a predictable order of execution, and coupling steps through unwritable contracts of “when someone somewhere eventually emits message B after message A, then I’ll do something..” isn’t really so workable.
That said, I’ve used message busses in many applications in the past where order of execution wasn’t of concern, and I 100% agree with you that they are absolutely lovely in those cases.
