I wonder if they migrated their infra over to facebook's, and if they're still running Erlang/OTP on FreeBSD boxes.
There is an interview where Jan mentions that "thanks to Facebook's infrastructure" they can use local servers in India to send msgs to and from, instead of going to Palo Alto all the time. It's unlikely, that the sever setup there has changed. It's unknown to me what the (new) decentralized infrastructure setup is