Can you elaborate? What role does Tailscale play? I selfhost and have heard about Tailscale but couldn't figure out how it's used.

Not GP. My guess is that they’re self hosting this at home (not on a server that’s on the internet), and Tailscale easily and securely allows them to access this when they’re elsewhere.

Tailscale routes my mobile device dns through my pile back at the home. I have nginx setup with easy to remember domains (photos.my domain.com) that work when i’m away as well without exposing anything to the open internet.

In my words, I use Tailscale at home but not for this (yet). Tailscale is a simple mesh network that joins my home computers and phones while on separate networks. Like a VPN, but only the phone to PC traffic flows on that virtual private network.

Tailscale can give you domains + ssl for local services with basically no effort.

With tailscale on your server and endpoints you can access the server from anywhere without even having to open any ports. It is like magic.

Tailscale gives me access to my home network when I'm not at home. I can be on a train, in another country even, and watch shows streamed off the Raspberry Pi in my home office.