River AI is a Palo Alto AI lab building personal frontier models and the full stack around them — training infrastructure, open-weight post-training, personal hardware for local inference, and next-generation interfaces. Co-founded by CEO Igor Babuschkin (ex-xAI/DeepMind), it came out of stealth in 2026, raised a large first funding round, and runs a Greenhouse board with research, hardware, ops and GTM roles, mostly on-site in Palo Alto.