If you're looking for a real-time federated social-network (that is what I understood by "Google Wave") solution have a look at solutions based on the industry standard XMPP. I'm building one (Movim https://movim.eu/) and started to explain how is made the architecture in this blog post https://nl.movim.eu/?blog/edhelas%40movim.eu/how-s-made-movi....
I wonder what folks here think about ActivityPub. I been craving for a federated protocol since Google Wave. I'm yet to go through it in detail and see if it really stands.