very cool, I’ll have to look more into it

what remote desktop protocol do they use?

Very cool. I personally use a double wireguard network: a wireguard vpn at home for all my services, and then since my home network is behind a double NAT and impossible to access publicly, I use a second wireguard tunnel to a VPS, to forward traffic to my internal wireguard network. The only thing the VPS can see is encrypted wireguard packets.

Edit: it seems like this service is more for public or shared services (like a public blog), rather than private personal services, so wireguard is less of an option

Sorry for necro but your ideology is fascinating. It sounds like you believe offline people deserve the same benefits as online people. Why do you believe this? Why shouldn’t the world move towards an expectation of online existence?

If I were to guess, your goal is not offline existence, but privacy, and doing things offline guarantees privacy, the same way that high-security environments use airgapped machines. But that’s just a means to an end. There are other ways of achieving privacy, like using vetted open source software that take privacy seriously, for example a fediverse client running in Tor browser. Privacy does not necessitate being offline. Going to a cafe to download articles to read offline, is not really offline either. It’s just an intermittent internet connection