@james "Serverless" doesn't really mean "without using servers", it just means being able to create and run applications without managing the backend. Nostr definitely meets that definition. A bunch of different relays running different flavors of relay software connecting a bunch of different applications together.

You are right that there is a scaling issue, since relays aren't especially elastic. Relays can share with each other, so you don't have to subscribe to all of them, but still.