I can only guess what was meant, but I suspect the main argument is that projection code in an event sourced system is much more nimble when it's not tied down

I can only guess what was meant, but I suspect the main argument is that projection code in an event sourced system is much more nimble when it's not tied down to an underlying schema. Documents make focusing on language level types much easier. That said, we've not built Crux with domain-level event sourcing in mind in particular. There is certainly overlap in the bitemporal model Crux has and what I gather some people are doing with retroactive events. This blog post on Datomic and event sourcing is interesting and relevant for Crux also (Crux has been heavily inspired by Datomic): https://vvvvalvalval.github.io/posts/2018-11-12-datomic-event-sourcing-without-the-hassle.html https://vvvvalvalval.github.io/posts/2018-11-12-datomic-even...