I have a real domain name for my house. I have a few publicly available services and those are listed in public DNS. For local services, I add them to my local DNS server. For ephemeral and low importance stuff (e.g. printers) mDNS works great.

For things like Home Assistant I use the following subdomain structure, so that my password manager does the right thing:

  service.myhouse.tld
  local.service.myhouse.tld