About this episode
Jean Lee discusses her experience building WhatsApp and the lessons learned from scaling the app.
Brought to You By: • Statsig — The unified platform for flags, analytics, experiments, and more. • Sonar – The makers of SonarQube, the industry standard for automated code review • WorkOS – Everything you need to make your app enterprise ready. — How did a tiny team of 30 engineers build the world-famous messaging app more than a decade ago, and what can dev teams learn from that feat today? Jean Lee was engineer #19 at WhatsApp , joining when the company was still small, with almost no formal processes. She helped it scale to hundreds of millions of users, went through the $19B acquisition by Facebook, and later worked at Meta. In this episode of Pragmatic Engineer , I talk with Jean about what it was like building WhatsApp. When Facebook bought WhatsApp in 2014, only around 30 engineers supported hundreds of millions of users across eight platforms. We discuss how the founders kept things simple, saying “no” to most feature requests for years. Jean explains why WhatsApp chose Erlang for the backend, why the team avoided cross-platform abstractions, and how charging users $1 per year paid everyone’s salaries, while keeping growth intentionally slow. Jean also shares what the…
People in this episode
Host: Gergely Orosz
Guest: Jean Lee
Topics covered
- engineering
- scaling
- acquisition
- AI
- development processes
Keywords
- Jean Lee
- engineering
- Facebook acquisition
- Erlang
- development processes
- AI
- messaging app
Sponsors
Statsig, Sonar, WorkOS
Mentioned in this episode
Organizations: WhatsApp, Facebook, Meta
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