Three Return to OpenAI, Organization Remains: What Is Happening at Mira Murati's New Company?
It has been reported that two co-founders (Barret Zoph and Luke Metz) of the AI startup "Thinking Machines Lab (TML)," launched by former OpenAI CTO Mira Murati, are "returning" to OpenAI. It is unusual for co-founders to leave a startup less than a year after its founding, indicating that the AI talent war is now affecting the very "lifeline" of companies: their co-founding teams.
1. What happened: The "story" was rewritten in 58 minutes
On Wednesday, Murati posted on X regarding co-founder and CTO Barret Zoph, stating, "We have parted ways," and explained that Soumith Chintala would be taking over as the new CTO.
However, about 58 minutes later, OpenAI (via Fidji Simo, CEO of the Applications division) posted that they were "welcoming Zoph, Metz, and Sam Schoenholz to OpenAI," revealing that the move had been "in progress for several weeks." As a result, TML found itself in a situation where the "transfer of co-founders" was confirmed immediately after the announcement of a "CTO change."
2. Why it matters: A startup's "credibility" resides in its co-founders
Co-founders are the core of technology, hiring, fundraising, and decision-making. Especially when the CTO is a co-founder, they externally serve as the "axis of research and development" and the "magnetic force for recruitment." TML attracted attention by gathering a stellar team of former top researchers, but the departure of multiple key figures in a short period easily creates doubts inside and outside the company, such as "Is the roadmap okay?" or "What happened to the organizational governance?" WIRED has also reported this event as a "blow."
2-1. The larger the funding scale, the more visible the governance instability
TML is reported to have raised approximately $2 billion in seed funding in July 2025 at a valuation of approximately $12 billion (led by a16z, with participation from Nvidia, AMD, Accel, Jane Street, and others).
Huge funding is "proof of expectations," but it also amplifies the "risk of failure to deliver." The departure of co-founders is one of the signals to which investors and job candidates react most sensitively.
3. OpenAI's goal: Talent is an asset directly linked to "model performance"
In AI development, not only computing resources but also top research and implementation talent are the competitive edge itself. Simo announced the addition of the three individuals and hinted at a structure where Zoph will function as a manager.
What is important here is that this is not just a job change, but that a cycle of "OpenAI → Emerging Force → OpenAI" is occurring at the forefront of competition. As Reuters has pointed out for some time, the AI industry has increasingly taken on the appearance of a "talent war."
4. Thinking Machines' next move: Can they "redefine" the blow?
Murati has appointed Soumith Chintala as the new CTO, praising him as a "leader who has contributed to the AI field for many years."
In the short term, the focus is on three points: (1) continuity of research and development, (2) recruitment competitiveness, and (3) accountability to investors and the market. Furthermore, TechCrunch reports that TML previously sent co-founder Andrew Tulloch to Meta, suggesting that these departures may not be "isolated incidents."
5. Implications for investors and business: A phase where the substance of the product determines "valuation"
This incident serves as a reminder that the value of an AI startup cannot be measured solely by "funding amount" or "former affiliation." According to Reuters, Murati initially stated that they would "share the first product within a few months" and also mentioned open-source elements.
That is why the future turning point is clear: moving from "who is there" to "what they release." Whether TML can overcome the headwind of co-founder departures with concrete products and results will determine their true worth.