I think nostr.band is what you think of as layer 2, or? I think @bruggeman fetches a lot of stuff, Indexes it and makes it available via an API for other clients. Don't know if it is available as a DVM yet.

nostr:npub1xtscya34g58tk0z605fvr788k263gsu6cy9x0mhnm87echrgufzsevkk5s did some interesting things developing nostrdb and can query insanely fast just on the client.

These are the two things coming to my mind right now