Explore how WhatsApp successfully implemented static typing with eqWAlizer across their entire codebase in this 27-minute conference talk from Code BEAM Lite Stockholm 2023. Discover the benefits of static typing for scaling large Erlang projects, the problems it addresses, and the reasoning behind not using Erlang for the type checker implementation. Gain insights into WhatsApp's code base history, the introduction of specs, and the challenges faced with existing tools like dialyzer. Learn about the development goals, graduality, types, and the Gradle timeline for implementing eqWAlizer. Conclude with key takeaways and a Q&A session to deepen your understanding of static typing in Erlang projects.