WhatsApp is a chatting application written in Erlang. Let us have a discussion on how WhatsApp managed to run 3 million TCP connections on each FreeBSD server.   WhatsApp has the following metrics 42 Billion messages a day 1 Billion users 3 Million connections!!   0:00 Intro 2:00 How WhatsApp reached 1,2 then 3 Million Connection 7:00 How Many Processes?  10:00 Server Side Load Balancing 13:50 Client Side Load Balancing   Resources https://blog.whatsapp.com/1-million-is-so-2011 https://blog.whatsapp.com/on-e-millio-n https://developers.facebook.com/videos/f8-2016/a-look-at-whatsapp-engineering-for-success-at-scale/   ? Backend Engineering Videos https://www.youtube.com/playlist?list=PLQnljOFTspQUNnO4p00ua_C5mKTfldiYT  ? Database Engineering Videos https://www.youtube.com/playlist?list=PLQnljOFTspQXjD0HOzN7P2tgzu7scWpl2  ? Network Engineering Videos https://www.youtube.com/playlist?list=PLQnljOFTspQUBSgBXilKhRMJ1ACqr7pTr  ? Load Balancing and Proxies Videos https://www.youtube.com/playlist?list=PLQnljOFTspQVMeBmWI2AhxULWEeo7AaMC  ? Postgres Videos  https://www.youtube.com/playlist?list=PLQnljOFTspQWGrOqslniFlRcwxyY94cjj  ?Docker https://www.youtube.com/playlist?list=PLQnljOFTspQWsD-rakNw1C20c1JI8UR1r  ? Programming Pattern Videos  https://www.youtube.com/playlist?list=PLQnljOFTspQV1emqxKbcP5esAf4zpqWpe  ? Web Security Videos https://www.youtube.com/playlist?list=PLQnljOFTspQU3YDMRSMvzflh_qXoz9zfv  ? HTTP Videos https://www.youtube.com/playlist?list=PLQnljOFTspQU6zO0drAYHFtkkyfNJw1IO  ? Python Videos https://www.youtube.com/playlist?list=PLQnljOFTspQU_M83ARz8mDdr4LThzkBKX  ? Javascript Videos  https://www.youtube.com/playlist?list=PLQnljOFTspQWab0g3W6ZaDM6_Buh20EWM  ?Discord Server https://discord.gg/CsFbFce  Become a Member  https://www.youtube.com/channel/UC_ML5xP23TOWKUcc-oAE_Eg/join  Support me on PayPal https://bit.ly/33ENps4  Become a Patreon https://www.patreon.com/join/hnasr?  Stay Awesome, Hussein