> Also, think about how you’ll want to control modules. If you intend to shut them down, query their health, etc. One way around this (which might be useful ev

> Also, think about how you’ll want to control modules. If you intend to shut them down, query their health, etc. One way around this (which might be useful even if there are multiple handlers per module) is to have explicit layers to the onion. That is, make the health checking stuff etc, belong to an outer layer that is different from where the application exposes it's API. The layers can still "grammar" (i.e. message protocol), but they are separate endpoints. I suspect (but do not know) that this lets the event protocol evolve more independently of the management framework. Which fits in with the OPs noble goal of keeping version 0 minimal. (In fact I think she wants to ignore what I called the "management framework" entirely).