So, it sounded interesting but they have bet too hard on the "developer marketing" playbook of "just give the minimum amount of explanation to get people to try the stuff".

For example, there is a quick start, so I skip that and click on "core concepts". That just redirects to quick start. There's no obvious reference or background theory.

If I was going to trust something like this I want to know the underlying theory and what guarantees it is trying to make. For example, what is included in a cache key, so that I know which changes will cause a new invocation and which ones will not.