Trust me, they've modified it heavily by now and probably use a bunch of side services that don't use it fully. It's a common pattern in messaging startups. Us

Trust me, they've modified it heavily by now and probably use a bunch of side services that don't use it fully. It's a common pattern in messaging startups. Use XMPP, find out ejabberd is the half-decent one, migrate slowly away from XMPP eventually. Facebook had a similar trajectory.