Does anyone knows if WhatsApp is still based on Erlang?
I’ve been using Erlang since the early 2010s, right around the time we (the tech industry) discovered that WhatsApp was supporting over 400 million active users with only like 30 engineers.
I reached out to one of their engineers at the time (when I still lived in the US) who kindly responded to some of my questions via email. We ended up meeting for coffee and still stay in touch to this day.
I can tell you that Erlang is still very much a part of WhatsApp.
I don't have access to anything anymore, but 30 engineers sounds about right.
At that time, I think was about Two on Nokia S40, two on S60, two on Blackberry, two on WP. I think three on Android, three on iOS. One or two on voip (shhh, it won't be out until summer 2014). I probably missed one or two people that floated around different client projects.
So, something like 17 on server?; we were not a 100% Erlang shop of course (our web page was just PHP, our blog was still Wordpress at that time (hiss), but I can only think of onen server person who wasn't doing much in Erlang.
There were also a lot of people wearing many hats. Several client team members had significant contributions to server work and some work the other way too.
Try as I might, I never did convince the S40 team to run Erjang though.