Mobile messaging service WhatsApp now has an incredible 1bn monthly active users, who send 42bn messages every single day. But perhaps more incredible is the fact WhatsApp has a staff of only 57 engineers. In fact, when Facebook bought the company for $19bn in early 2014 they employed just 35 engineers and fewer than 50 people in total.
How is it possible to create such a valuable company that can scale to support such a vast user base with so few human resources? Benedict Evans said in his weekly newsletter this morning that, “Software means you can stand on the shoulders of giants, and do it with very little capital.” In other words, the advances made by others in the fairly recent past enable small teams to do some (really) big things.
Specifically, in the case of WhatsApp, the team chose a fairly low profile programming language called Erlang which offer some distinct advantages, as detailed in this Wired profile piece from late last year:
In using Erlang, WhatsApp is part of a larger push towards programming languages that are designed for concurrency, where many processes run at the same time. As internet services reach more people—and juggle more tasks from all those people—such languages become more attractive.
Erlang is a product of the ’80s. Engineers at Ericsson, the Swedish multinational that builds hardware and software for telecom companies, developed the language for use with high-speed phone networks. “Instead of inventing a language and then figuring out what to do with it, they set out to invent a language which solved a very specific problem,” says Francesco Cesarini, an Erlang guru based in the UK. “The problem was that of massive scalability and reliability. Phone networks were the only systems at the time who had to display those properties.”
What’s more, Erlang lets coders work at high speed—another essential part of modern software development. It offers a way of deploying new code to an application even as the application continues to run. In an age of constant change, this is more useful than ever.
Now excuse me while I go and reply to a new message…