Comment by tabbott

(1) Not currently, though you can certainly imagine doing it and having it work well; the core data model doesn't change very much over time.

(2) There's a reasonably well-specific API, and you could imagine building an independent implementation that fit that API and feeling good about doing so. But I feel like that would probably be a lot of work and you could probably much more easier achieve whatever your actual goal without paring down the dependencies very much.

E.g. the relatively high minimum recommended RAM for a Zulip server is mostly due to running 20 Python processes for all the queue workers, most of which are idle all the time. If we wanted to decrease the memory requirements, there's a variety of ways to solve that problem directly that are a lot easier than doing a rewrite :).