Toby Pohlen, a co-founder of xAI, has left the company, becoming the fifth co-founder to depart and intensifying questions about the long-term stability of Elon Musk's AI venture. Pohlen came to xAI from DeepMind, where he worked on distributed systems for large-scale AI training — the complex infrastructure required to coordinate thousands of GPUs working in parallel.
His expertise was considered particularly valuable given xAI's ambitious plans to build one of the world's largest training clusters in Memphis, Tennessee. At xAI, Pohlen helped design the training infrastructure that enabled Grok's development, applying lessons learned from DeepMind's distributed training work to xAI's unique hardware configuration.
With Pohlen's departure, a majority of xAI's original co-founding team has now left the company, a rate of attrition that is highly unusual for a startup less than three years old with billions in funding. The pattern of departures, primarily of researchers from DeepMind and Google Brain backgrounds, points to a fundamental tension between the academic research culture these scientists are accustomed to and the fast-paced, Musk-driven operational style that defines xAI.
