Meta describes how a small team built Forum, a standalone app for deeper conversations in Facebook Groups, by treating an AI agent as a participant in the engineering process rather than merely a code autocomplete tool. The team shifted toward a human-on-the-loop model: engineers define goals, monitor agent runs, intervene when needed, and approve outcomes, while agents plan, implement, build, test, correct, and repeat. Meta measured verified production-ready changes rather than code volume, requiring automated builds, tests, visual checks, and recorded verification before review. To support this workflow, the team decomposed work into precise, machine-readable specifications; added rules, reusable skills, commands, and hooks; and embedded pass/fail signals into the agent loop. Navigation agents interacted with the live app through simulator view hierarchies and repeatable user paths, while production agents investigated feedback and possible regressions. Meta also created a separate sandbox build flavor so prototypes could use the same codebase and design system without prototype code entering the production build. Stress scenarios such as aggressive scrolling, random browsing, rapid navigation, and repeated media loading exposed a memory problem before launch; the verified fix roughly halved memory use and page faults across repeated sessions. Meta says Forum reached core feature parity with Facebook Groups in eight weeks, with engineers retaining responsibility for architecture, product goals, and final quality judgments. The article presents the approach as an ongoing target rather than a fully autonomous system, and emphasizes that better context, clearer architecture, and trustworthy verification mattered more than improved prompting.
