Barret Zoph Departs OpenAI for the Second Time — Leaves Head-of-Enterprise-AI Role Five Months After Returning From Thinking Machines Lab

Barret Zoph, OpenAI's head of enterprise AI sales, has departed the company approximately five months after rejoining in mid-January 2026, marking his second exit from OpenAI in roughly 18 months. Zoph had originally left OpenAI in late 2024 to co-found Thinking Machines Lab as CTO alongside Mira Murati, but returned to OpenAI after being terminated from Thinking Machines amid contested workplace allegations; prior reporting indicated Thinking Machines told staff Zoph had an undisclosed workplace relationship before his termination. OpenAI and Zoph have not publicly explained the reasons for this latest departure, which arrives as the company advances its IPO preparation.