Hot replacement upon incoming/outgoing Kafka message

[gunnarmorling]

Details of this are a bit blurry to me, but essentially, what I'd want is to have hot code replacement without having to refresh an application's web view when

• receiving an inbound Kafka message after a code change
• emitting a Kafka message e.g. from af Flowable after a code change

Perhaps it could be expanded to work with Reactive Messaging in general, but using Kafka made me wish for this. I might also be able to help out with it provided someone can give me some general hints on where to hook this in.

[gsmet]

Closing in favor of #3217 .