[sligor]

> I can't imagine the whole thing can't be done with between 30 to 50 engineers in total.

How WhatsApp served 1 billion users with only 50 engineers. https://blog.quastor.org/p/whatsapp-scaled-1-billion-users-5...

edit: https://news.ycombinator.com/item?id=28985169

[em500]

At the time WhatsApp was only forwarding messages from user to user. They didn't deal with different contracts and license deals in 180 countries. Nowadays they have a lot more country specific regulations to deal with, and also a much higher headcount.