Sounds like he is running a steam cache out of Chicago and Germany so likely running it off of a VPS service for now.
Honestly if he gets this working really well (especially on linux / steamdeck) this could be an excellent aquire + hire by valve.
I don’t think they are hosting it? Seems like client side cache layer calling steam DL APIs?
Are you asking if that's what they are doing?
Hm, I think they talked about the server some... It's possible there's a server coordinating things and the client talks to steam for the actual data, but that sounds (even more) complicated.