Once something is merged to master in zulip.git, it's usually on zulipchat.com production within a few days. So if you do it in a way that gets merged (which r

Once something is merged to master in zulip.git, it's usually on zulipchat.com production within a few days. So if you do it in a way that gets merged (which requires, e.g., automated tests appropriate for an authentication backend) and is configurable for just one organization in a multi-organization server, you would not need to host your own servers.