From Wired:
One of the (many) intriguing parts of the WhatsApp story is that it has achieved such enormous scale with such a tiny team. When the company was acquired by Facebook, it had 35 engineers and reached more than 450 million users. Today, it employs only about 50 engineers, though the number of WhatsApp users has doubled, and this tiny engineering staff continues to run things almost entirely on its own. In a world where so many internet services are rapidly expanding to millions upon millions of users, WhatsApp shows the way forward—at least in part. Software engineer Jamshid Mahdavi joined WhatsApp about two years ago, after the startup was up and running, and its approach to engineering was unlike any he had seen—in part because it used Erlang and a computer operating system called FreeBSD, but also because it strove to keep its operation so simple. “It was a completely different way of building a high-scale infrastructure,” he said on Monday. “It was an eye-opener to see the minimalistic approach to solving … just the problems that needed to be solved.”