How about IPFS? OpenBazaar is an IPFS case study. They recently released a revamped v2 built with Go.
Yeah, I'd look at IPFS's networking library, libp2p. It's the peer-to-peer backbone of IPFS and has a big community and active development https://libp2p.io/ . It's also implemented in both go and js (as most of IPFS is)
EDIT: I'm referring to the JS version here.