Does dang run HN on a single server? Why does HN use Algolia for search and Firebase for its API?

"Using an old phone or laptop as server means you'll end up with a single digit annual electricity bill for that."

The largest possible single digit annual electricity bill would be $9. That's almost enough to run a 3W device 24x7 for a year. Do you know any old phone or laptop that can serve as a reliable Jitsi server yet draws an average of 3W or less?