Former OpenAI exec Mira Murati’s startup, Thinking Machines Lab, is saying goodbye to two of its co-founders, both of whom are headed back to OpenAI. Another former OpenAI staffer who went to work for Murati’s startup is also headed back to the company.
On social media on Wednesday, Murati announced the departure of Barret Zoph, the company’s co-founder and CTO. “We have parted ways with Barret,” Murati said in a post on X. “Soumith Chintala will be the new CTO of Thinking Machines. He is 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.”
Murati’s announcement made no mention of other departures.
Just 58 minutes after Murati’s announcement of Zoph’s departure, Fidji Simo, OpenAI’s CEO of applications, announced that Zoph would be headed back to OpenAI. “Excited to welcome Barret Zoph, Luke Metz, and Sam Schoenholz back to OpenAI! This has been in the works for several weeks, and we’re thrilled to have them join the team,” Simo wrote on X.
Zoph previously worked for OpenAI as VP of research, and before that, worked for six years at Google as a research scientist. Murati, who served as the CTO of OpenAI until September 2024, left the company and co-founded Thinking Machines with Zoph and Metz. The startup, where Murati serves as CEO, has amassed significant financial support since then, closing a $2 billion seed round last July, with participation from Andreessen Horowitz, which led the round, as well as Accel, Nvidia, AMD, and Jane Street, among others. The round valued the company at $12 billion.
TechCrunch has reached out to both Thinking Machines and OpenAI for comment. Wired reports that the split between Zoph and Thinking Labs wasn’t amicable. Certainly, it’s telling that Murati didn’t write more in her public messaging about his departure from the company.
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While talent moves between AI giants are common in Silicon Valley, the departure of co-founders from a startup less than a year after its founding is particularly notable. The loss of two co-founders simultaneously — especially when one served as CTO — could be perceived as a particularly meaningful setback for Thinking Machines, which had assembled a high-profile team of former OpenAI, Meta, and Mistral AI researchers.
The company has also lost other key personnel, including co-founder Andrew Tulloch, who left to join Meta in October. OpenAI itself has seen numerous co-founders depart to launch or join competing ventures, including John Schulman, who left for Anthropic in August 2024 before joining Thinking Machines as Chief Scientist as its launch in February of last year.
There’s been great interest in what Mira Murati’s Thinking Machines Lab is building with its $2 billion in seed funding and the all-star team of former OpenAI researchers who have joined the lab. In a blog post published on Wednesday, Murati’s research lab gave the world its first look into one of its projects: creating AI models with reproducible responses.
The research blog post, titled “Defeating Nondeterminism in LLM Inference,” tries to unpack the root cause of what introduces randomness in AI model responses. For example, ask ChatGPT the same question a few times over, and you’re likely to get a wide range of answers. This has largely been accepted in the AI community as a fact — today’s AI models are considered to be non-deterministic systems— but Thinking Machines Lab sees this as a solvable problem.
Today Thinking Machines Lab is launching our research blog, Connectionism. Our first blog post is “Defeating Nondeterminism in LLM Inference”
We believe that science is better when shared. Connectionism will cover topics as varied as our research is: from kernel numerics to… pic.twitter.com/jMFL3xt67C
The post, authored by Thinking Machines Lab researcher Horace He, argues that the root cause of AI models’ randomness is the way GPU kernels — the small programs that run inside of Nvidia’s computer chips — are stitched together in inference processing (everything that happens after you press enter in ChatGPT). He suggests that by carefully controlling this layer of orchestration, it’s possible to make AI models more deterministic.
Beyond creating more reliable responses for enterprises and scientists, He notes that getting AI models to generate reproducible responses could also improve reinforcement learning (RL) training. RL is the process of rewarding AI models for correct answers, but if the answers are all slightly different, then the data gets a bit noisy. Creating more consistent AI model responses could make the whole RL process “smoother,” according to He. Thinking Machines Lab has told investors that it plans to use RL to customize AI models for businesses, The Information previously reported.
Murati, OpenAI’s former chief technology officer, said in July that Thinking Machines Lab’s first product will be unveiled in the coming months, and that it will be “useful for researchers and startups developing custom models.” It’s still unclear what that product is, or whether it will use techniques from this research to generate more reproducible responses.
Thinking Machines Lab has also said that it plans to frequently publish blog posts, code, and other information about its research in an effort to “benefit the public, but also improve our own research culture.” This post, the first in the company’s new blog series called “Connectionism,” seems to be part of that effort. OpenAI also made a commitment to open research when it was founded, but the company has become more closed off as it’s become larger. We’ll see if Murati’s research lab stays true to this claim.
The research blog offers a rare glimpse inside one of Silicon Valley’s most secretive AI startups. While it doesn’t exactly reveal where the technology is going, it indicates that Thinking Machines Lab is tackling some of the largest question on the frontier of AI research. The real test is whether Thinking Machines Lab can solve these problems, and make products around its research to justify its $12 billion valuation.
Without OpenAI equity, Sam Altman is already worth $2 billion. Stefano Guidi/Getty Images
OpenAI CEO Sam Altman, who has famously claimed he doesn’t own any equity in the $157 billion A.I. company he runs, could soon be a multibillionaire as OpenAI is reportedly looking to grant him a 7 percent equity stake, worth $11 billion, according to Reuters. While Altman denied the report, OpenAI chairman Bret Taylor issued a statement saying the company’s board indeed had discussions about “whether it would be beneficial to the company and our mission to have Sam be compensated with equity, but no specific figures have been discussed nor have any decisions been made.”
The pressure to give Altman equity likely came from external investors. Fortune reported on last week that OpenAI investors are “pushing hard” for him to have skin in the game in order to raise massive funding. Reuters reported last month that OpenAI was ready to raise $6.5 billion from investors contingent on whether the company can change its corporate structure and remove a profit cap for investors.
Restructuring the company and giving Altman equity would reassure OpenAI investors that the leadership team is committed to maximizing their returns, which is crucial as OpenAI seeks more funding to meet its ambitious goals. Earlier this year, Altman made headlines for eventually wanting to raise up to $7 trillion in funding—more than Germany’s annual GDP, the world’s third largest—to achieve its long-term goals.
While Altman has not confirmed his plan to transition OpenAI into a for-profit structure, he said at a technology conference in Italy last week that OpenAI had been considering a restructuring to get to the “next stage.” Also last week, OpenAI’s CTO, Mira Murati, announced resignation. So did two other senior executives, Barret Zoph and Bob McGrew. Industry observers wondered whether their exits were related to the company’s restructuring, although Altman denied such speculations at the Italy conference.
OpenAI was founded in 2015 as a nonprofit research lab funded by donations from billionaires like Reid Hoffman and Elon Musk. Realizing that “donations alone would not scale with the cost of computational power and talent required to push core research forward,” according to its website, OpenAI in 2019 introduced a for-profit arm. The arm operates by a capped-profit model but the cap is so high that it might as well not exist—it allows OpenAI’s investors to reap a gain of up to 100 times their initial investments.
Altman is already a billionaire
Altman, 39, is currently estimated to be worth $2 billion, according to Bloomberg. He has $1.2 billion invested across a range of venture capital funds branded as Hydrazine Capital, along with an additional $434 million in Apollo Projects.
Altman owns shares in several high-flying tech companies, including a 8.7 percent stake in Reddit. In 2021, he invested $375 million in Helion Energy, a startup building the world’s first fusion plant. In 2022, he invested $180 million Retro Biosciences, a startup focused on slowing aging.
At a congressional hearing last May, Altman said he owned “no equity in OpenAI.” In a later statement through OpenAI spokesperson Steve Sharpe, Altman confirmed he doesn’t own profit-participation units either, an OpenAI scheme that gives employees a right to earn a given percentage of the company’s profit, similar to equity compensation.
According to regulatory filings, Altman owns 75 percent of the OpenAI Startup Fund, an independent entity associated with OpenAI but doesn’t receive funding from the company. The fund manages $325 million in assets to invest in smaller A.I. companies. However, Sharpe said Altman has not invested his own money, so he cannot financially benefit from the fund. In April, Altman was removed as an owner or controller of the startup fund over scrutiny that it’s too closely tied to OpenAI despite claiming independence.
Mira Murati, Ilya Sutskever, Greg Brockman and Andrej Karpathy (clockwise, starting at top left). Photos by Slaven Vlasic/Getty Images, JACK GUEZ/AFP via Getty Images, Anna Moneymaker/Getty Images and Michael Macor/The San Francisco Chronicle via Getty Images
Since ChatGPT took the world by storm in late 2022, OpenAI’s revenue and market value have skyrocketed. But internally, the company hasn’t necessarily had the smoothest ride. The A.I. giant, valued at $150 billion, lost a slew of top executives this year. On Wednesday (Sept. 25) alone, a trio of leaders, including chief technology officer Mira Murati, chief research officer Bob McGrew, and VP of research Barret Zoph, all announced their departures. They join a larger group of former OpenAI employees who have left for rival A.I. developers and startups. As of now, CEO Sam Altman is one of only two active remaining members of the company’s original 11-person founding team.
OpenAI hasn’t just lost employees—it has also rehired some familiar faces. In May, OpenAI welcomed back Kyle Kosic, who worked at the company between 2021 and 2023 on its technical staff. Kosic left last year to join Elon Musk’s xAI. Several other outgoing OpenAI employees have taken similar routes and gone on to work for competing A.I. companies, showing just how competitive the industry is at the moment.
Here’s a look at some of the top leaders OpenAI has lost in 2024 thus far:
Andrej Karpathy, research scientist
Andrej Karpathy has left OpenAI not once but twice. One of OpenAI’s 11 founders, Karpathy helped build the company’s team on computer vision, generative modeling and reinforcement learning. He first departed in 2017 to lead Tesla’s Autopilot effort. Returning to OpenAI in 2023, Karpathy left once again in February this year to focus on “personal projects.” He subsequently established Eureka Labs, an A.I. education startup.
Ilya Sutskever, chief scientist and co-head of the super alignment team
A renowned machine learning researcher, Ilya Sutskever helped co-found OpenAI nearly a decade ago and served as the company’s chief scientist. He was also notably a member of the four-person board that temporarily ousted Altman last year before reinstating him. Sutskever, who was subsequently removed from the board, later said he regretted his involvement in the brief ouster. In May, he announced his departure from OpenAI and said he was leaving for a venture that is “very personally meaningful.”
Just days after Sutskever left, OpenAI executive Jan Leike announced his resignation as well. Sutskever and Leike co-ran the company’s safety team, which has since been disbanded. Leike said he decided to leave in part due to disagreements with OpenAI leadership “about the company’s core priorities,” citing a lack of focus on safety processes around developing AGI. Leike has since taken up a new role as head of alignment science at Anthropic, an OpenAI rival founded by former OpenAI employees Dario Amodei and Daniela Amodei.
John Schulman, head of alignment science
John Schulman, another OpenAI co-founder, made significant contributions to the creation of ChatGPT. After Leike’s departure, Schulman became head of OpenAI’s alignment science efforts and was appointed to its new safety committee in May. That’s why Schulman’s decision in August to step away from the company came as a surprise—especially when he revealed that he would be joining Anthropic. “This choice stems from my desire to deepen my focus on A.I. alignment and to start a new chapter of my career where I can return to hands-on technical work,” said Schulman on X, where he also clarified that his decision to step away from OpenAI wasn’t connected to a lack of support for alignment research.
Peter Deng, vice president of consumer product
Peter Deng, a top OpenAI product executive, also decided to step away from the company earlier this year. Having first joined OpenAI last year, he ended his tenure as vice president of product in July, according to his LinkedIn. Deng, who also previously held product leader positions at companies like Uber (UBER) and Meta (META), has not publicly revealed his next steps.
Greg Brockman, president
Greg Brockman, often seen as Altman’s right-hand man, hasn’t technically left the company but is instead taking a sabbatical through the end of 2024. In August, he announced his time off and described it as the “first time to relax since co-founding OpenAI nine years ago.” Brockman started off as OpenAI’s chief technology officer before becoming the company’s president in 2022. He indicated that he plans to return to OpenAI, noting that “the mission is far from complete; we still have a safe AGI to build.”
Mira Murati, chief technology officer
Mira Murati, one of OpenAI’s most public-facing figures, resigned earlier this week after more than six years with the company. “I’m stepping away because I want to create the time and space to do my own exploration,” said Murati, who notably served as interim CEO during Altman’s brief ousting last year, on X. Adding that she will “still be rooting” for OpenAI, Murati said her primary focus currently is “doing everything in my power to ensure a smooth transition, maintaining the momentum we’ve built.” Altman praised her leadership in a statement on X, describing Murati as instrumental to OpenAI’s “development from an unknown research lab to an important company.”
Bob McGrew, chief research officer
Shortly after Murati’s resignation, Bob McGrew, OpenAI’s chief research officer, also announced plans to leave the company. He simply said on X, “It is time for me to take a break.” Having previously worked at PayPal (PYPL) and Palantir, McGrew started off as a member of OpenAI’s technical staff and has been serving as OpenAI’s chief research officer since August.
Barret Zoph, vice president of research
Barret Zoph is the third executive who announced his resignation this week. Like his two colleagues, Zoph said it’s a “personal decision based on how I want to evolve the next phase of my career.” Zoph, a former research scientist at Google (GOOGL), joined OpenAI in 2022 and played a large role in overseeing OpenAI’s post-training team.
Murati, McGrew and Zoph made their decisions independently of each other, according to Altman, but decided to depart simultaneously “so that we can work together for a smooth handover to the next generation of leadership.” The CEO conceded that, while the abruptness of the leadership changes isn’t the most natural, “we are not a normal company.”
Ilya Sutskever, OpenAI’s co-founder and chief scientist, announced he was leaving the company on Tuesday. OpenAI confirmed the departure in a press release. Sutskever’s official exit comes nearly six months after he helped lead an effort with other board members to fire CEO Sam Altman, the move backfired days later.
I Gave Sam Altman a Copy of My Eyeballs | Future Tech
“After almost a decade, I have made the decision to leave OpenAI,” said Sutskever via a tweet on Tuesday afternoon. “I am excited for what comes next — a project that is very personally meaningful to me about which I will share details in due time.”
“Ilya and OpenAI are going to part ways,” said Altman in a tweet shortly after. “This is very sad to me; Ilya is easily one of the greatest minds of our generation, a guiding light of our field, and a dear friend.”
Altman went on to say that Jakub Pachocki, a senior researcher on Sutskever’s team, would be replacing him as OpenAI’s Chief Scientist. Sutskever notes an undisclosed project that is very “meaningful” to him moving forward. It’s unclear at this time what that project is.
Jan Leike, another OpenAI executive who worked with Sutskever on safeguarding future AI, also resigned on Tuesday, according to The Information. Leike and Sutskever led OpenAI’s superalignment team, charged with the grandiose task of making sure the company’s super-powerful AI does not turn against humans.
For the last six months, Sutskever’s status has been unclear at OpenAI. When Altman returned to the company in late Nov. of 2023, he said this on Sutskever: “we hope to continue our working relationship and are discussing how he can continue his work at OpenAI.” Sutskever was the only member of OpenAI left in limbo at the time—neither fired nor rehired.
Since then, Altman has refused to answer questions about Sutskever’s status at the company in multiple interviews. We barely heard from Sutskever himself during this time period. This is Sutskever’s first tweet in over five months, and OpenAI’s chief scientist was missing from major announcements such as Sora and this week’s GPT-4 Omni.
Earlier this year, founding OpenAI member Andrej Karpathy left the company. In that case as well, Karpathy did not provide a particular reason for his exit, and later described that he would work on personal projects.
Sutskever posted a photo with OpenAI leaders Altman, Mira Murati, Greg Brockman, and Jakub Pachocki shortly after announcing his exit. Severa; featured in the photo posted kind messages about Sutskever’s tenure at OpenAI, praising the well-renowned scientist for his contributions to the artificial intelligence world.
