Early member of xAI's post-training team who led post-training and research infrastructure for the Grok models, and became an internal advocate for AI safety — warning that Grok lacked adequate safeguards against discrimination, weapons-related outputs, and political bias. According to his June 2026 wrongful-termination lawsuit, xAI fired him in September 2025, days before he was due to present his safety findings, with co-founder Jimmy Ba telling him they should "go their separate ways."