We found our first use-case for #RubyEventStore / #RailsEventStore projection at $DAYJOB: analytics.

We publish events regarding a certain process, and we want to derive metrics about the process. Since the events are already in the database, the projection allows us to go "back in time" and extract the metrics from the existing event stream.

In contrast, in a stateful system, the metrics would not be derivable for past objects, only for new changes happening in the system.

I'm trying to mash up all kinds of things together at once:

#Hanami 2.0 RC1
#ROM
#RubyEventStore from #RailsEventStore

All of these are *designed* to work together, but the going is rough.

My current status is this patch: https://github.com/francois/LetsMeet/pull/1

The Hanami console boots, but I can't access the event store due to an `ArgumentError: missing keyword: :serializer`. Will sleep on it and see if I can get more progress tomorrow.

Yes, I am following the Hanami 2.0 guide to implement persistence