Mira Murati

It’s been almost two years since Mira Murati left OpenAI, where she was CTO as the company built ChatGPT, and a little more than a year since she publicly launched her own company, Thinking Machines Lab. She positioned Thinking Machines as a company devoted to AI’s most consequential applications. To do that, she raised $2 billion—the largest seed round for a startup ever, with a $12 billion valuation. In early 2026, talent departures were extensively reported, although the startup’s staff now numbers more than 150, four times its size at launch. So far, the lab has released Tinker, a developer tool for customizing large AI models. Compared to AI leaders like OpenAI and Anthropic (led by Murati’s former colleagues), Thinking Machines Lab is still young. But it has the backing of major players like Nvidia, which in 2026 invested in the lab and signed on to a multiyear strategic partnership to support Thinking Machines’ frontier model training.