> when I looked, it seemed you got the complexity of serving 10k users even if you only had 100s.

haha, that's a good way to put it. We've put in a lot of work over the last few months to make Zulip easier to deploy for a team of 20.

> Last I looked, only rocket.chat had a sane, minimal docker-compose setup

Fair enough! It's on our roadmap, so hopefully we'll have it by the next time you're looking for a chat :).