Meta built the modern social graph through Facebook, Instagram, and WhatsApp. After a costly VR pivot under the "Metaverse" rebrand, Zuckerberg refocused the company on AI. FAIR (Fundamental AI Research) had published significant academic work for years; the commercial bet shifted in 2023 when Meta released LLaMA as open weights. Subsequent Llama releases have established Meta as the primary source of production-grade open-source language models. The Ranking Engineer Agent — Meta's autonomous ML pipeline for ads — represents the most detailed public account of an AI agent replacing engineering workflow steps at scale.