Ex-OpenAI executive Mira Murati’s AI startup, Thinking Machines Lab, has suffered another high-profile departure as top executive Jolene Parish has left to rejoin her former boss’s firm, OpenAI. The move intensifies the public tensions and talent wars between the two AI powerhouses.
Parish joined Thinking Machines Lab in April 2025 but has now returned to OpenAI, where she previously spent three years. Before that, she worked at Apple for a decade. Her exit follows a string of similar defections from Murati’s venture back to Altman’s OpenAI.
Wave of departures hits Murati’s startup
In January 2026, Thinking Machines Lab’s co-founder and chief technology officer, Barret Zoph departed amid controversy. Murati announced the split on X (formerly Twitter), stating, “We have parted ways with Barret Zoph.” She quickly named Soumith Chintala as the new CTO, praising him as “a brilliant and seasoned leader who has made important contributions to the AI field for over a decade, and he’s been a major contributor to our team. We could not be more excited to have him take on this new responsibility.”
Zoph’s departure was not on good terms. Reports indicate that Murati terminated him over performance issues and “unethical conduct,” including an undisclosed workplace relationship with another leadership-role employee that strained relations after Murati confronted him last summer (mid-2025). OpenAI disputed some of these claims in an internal memo.
Shortly after, Zoph was joined by co-founder Luke Metz and researcher Sam Schoenholz in returning to OpenAI. OpenAI’s CEO of Applications, Fidji Simo, announced the hires enthusiastically, noting the process had been in the works for weeks. Additional staffers, including researchers Lia Guy and Ian O’Connell, have also reportedly left Thinking Machines Lab in recent months, with some heading to OpenAI.
What could these defections mean for Thinking Machines Labs
Murati, who served as OpenAI’s CTO until September 2024, founded Thinking Machines Lab as a direct competitor focused on advancing multimodal AI. The startup quickly raised massive funding — a $2 billion seed round in July 2025 that valued it at $12 billion, backed by investors like Andreessen Horowitz, Accel, Nvidia, AMD, and Jane Street.
The repeated poaching of key talent, particularly founding members and early hires who originally came from OpenAI, highlights the fierce competition in the AI sector. These moves strengthen OpenAI’s team while putting pressure on the young Thinking Machines Lab, which has now lost several core figures less than a year after launch.