WhatsApp famously ran hundreds of millions of simultaneous connections with a very small engineering team, a feat widely credited to its choice of Erlang, a language built for telecom-grade concurrency and fault tolerance.
What we cover in the quiz
- Erlang was built for telecom switches, so it was already designed for massive concurrency and fault tolerance. That let a WhatsApp team of a few dozen engineers support hundreds of millions of users without a huge headcount.