Per his LinkedIn profile, Gross joined Meta this March and is part of the company’s engineering leadership team. At Thinking Machine Labs, Gross was a founding member of the technical staff.
Gross is the fifth founding member to leave the startup in recent months, according to Business Insider, which first reported the development. The firm has recently seen several departures for other major players. Sam Altman’s OpenAI hired the startup’s former chief technology officer (CTO) Barret Zoph and cybersecurity specialist Jolene Parish in January and February this year, respectively. Meta hired the startup’s co-founder Andrew Tulloch last August.
Thinking Machines Lab was founded by Mira Murati, previously the CTO at OpenAI. The startup reportedly raised $2 billion in a seed round led by venture capital firm a16Z at a $12 billion valuation in July 2025. In October 2025, the company launched Tinker, its first product, which is a flexible API for fine-tuning a language model. A flexible API is an interface designed to adapt to a developer’s needs rather than forcing them to follow a single, rigid path.
Murati’s startup has grown to around 130 employees since its founding in February 2025, per the Business Insider report. The company has also made high-profile hires of its own, including Soumith Chintala, who had previously worked at Meta, as CTO, and Neal Wu. Wu has been a three-time gold medallist at the International Programming Olympiad and also served as a founding member of the AI coding startup Cognition, valued at $10 billion.