You know what would be neat? An #activitypub server that can host multiple (small) instances.
Like if I want to have my own instance, and a bunch of my friends or some small groups that I am adjacent to but not necessarily a part of, the maintenance overhead of running e.g. a masto instance doesn't make that feasible to happen for each of those cases.
But if I could run one server, and then host people in their own space on common resources (storage, email api, image pipelines…) that'd work!