Barret Zoph returns to Google as vice president of research after brief OpenAI stint

Barret Zoph, a co-founder of the startup Thinking Machines who was dismissed from the company in January, has been appointed vice president of research at Google, his third senior role in less than a year. Google confirmed the hire and said Zoph will bring his expertise in reinforcement learning (RL) and post-training to the Gemini project.

Zoph spent two years at OpenAI before leaving in October 2024 to launch Thinking Machines with Mira Murati, who had departed the lab a month earlier. In January 2025, a second co-founder, Luke Metz, unexpectedly left the startup and returned to OpenAI, an event that later proved to be Zoph’s termination from the company he had helped create.

The OpenAI comeback was short-lived. Zoph survived only five months as head of enterprise sales before exiting in June 2025. The rapid shift from a senior research role to sales and then out of the company altogether suggests a mismatch or a sudden change in direction at a firm that is preparing for its first public offering.

At Google, where Zoph previously worked, he is back in a research-focused position as vice president of research with a focus on RL and post-training for Gemini. Google did not disclose the size of the team or the scope of authority, but the appointment signals that the company views those areas as a critical lever for the next generation of its models.

Zoph’s movements illustrate a broader trend of senior-level turnover at OpenAI. The rate of departures among top executives, from the chief operating officer to senior data-center leaders, is unusually high for the industry. A company gearing up for an IPO while losing the architects of its technical infrastructure raises questions about managerial stability and the ability to retain institutional knowledge as large sums of capital flow in.