How Meta Built Forum With AI-Native Engineering

TL;DR

Meta’s small Forum team needed to build a standalone Facebook Groups app quickly without turning AI-generated code into extra debugging and review work. They simplified the codebase and gave AI agents tools to plan, implement, test, and verify changes, while engineers retained architectural decisions and final approval. Forum reached core feature parity in eight weeks, and automated stress testing caught a pre-launch issue whose fix roughly halved memory use and page faults.