Gregory's Server
Boring #Smithereen update: I changed the user and post URIs. User URIs now have the form of /users/123 with my internal database IDs, these are only visible through #ActivityPub. Post URIs no longer have username part in them because that was redundant anyway — this ain't a highload system, I'm not doing load balancing based on "owner ID".
Next step: making sure this thing is able to federate with itself, + implementation of my specific features in ActivityPub.