Okay, now you have to support a Docker cluster, backups for persistent data, and deal with things like DNS, proxy, etc. management. It's easier than doing those from scratch but it's still a non-zero amount of work which will at best take time away from that small side project and at worst cause major problems if you never come back to installing security updates, running backups, testing the restore process, etc.

LOL... Dokku on DO is pretty simple... as to backups, it's a checkbox option, as to redundancy, for non-revenue generating projects, it's generally acceptable to have some down time. As to back up again, beyond some potential data loss, it's pretty easy to get CI/CD up and pushing to Dokku.

In any case, it doesn't need to be as completely flushed out as a company with millions in investment capital could do.

+1 on this, love Dokku myself. Great option for self-hosting and can even do some redundancy with multiple servers behind a load balancer.