You're right, it can't do some calculation across all data for a single user or session or anything like that. I suppose I was thinking that it might reduce "j

You're right, it can't do some calculation across all data for a single user or session or anything like that. I suppose I was thinking that it might reduce "just a little", just adding stuff together as appropriate, but that wouldn't really be useful. In practice, the way multiple events turn into a single event is that some are just thrown out, according to some static filter rule, or after checking a datastore. The places where NSQ are typically used is where new data never stops flowing. So sometimes for this sort of thing, it updates a value in some datastore, and creates a new message for the next stage with the latest value, perhaps only if the latest value reaches some threshold, in a scheme where the value decays.