" That's not even talking about the servers needed to serve a high volume CRUD app with built in messaging platform. "

Nah, people use way too much bloatware in that stuff. OKCupid had a big advantage over its competitors back in the day because they wrote fast code that saved them a ton of bucks on servers. Some of it is FOSS now: see okws.org . These days I'd consider seastar.io as an alternative.