"core bussiness" is finding and dispatcching drivers including payments. Everything in-app. > I can't imagine trying to deal with 1m+ concurrent tcp connection

"core bussiness" is finding and dispatcching drivers including payments. Everything in-app. > I can't imagine trying to deal with 1m+ concurrent tcp connections. 2 million connections on a BSD mchine is doable though not trivial and that too even in 2012. https://blog.whatsapp.com/1-million-is-so-2011 https://blog.whatsapp.com/1-million-is-so-2011