Thinking Machines Co-founder Andrew Tulloch Heads to Meta

The revolving door of AI talent continues. Andrew Tulloch, co-founder of Thinking Machines Labs, has left the company to join Meta, according to reporting by The Wall Street Journal. Andrew Tulloch's title at Thinking Machines Labs was "Chief Architect".

Tulloch’s departure comes just months after Thinking Machines made headlines for raising the largest seed round in history, led by a group of high-profile Silicon Valley investors betting on its promise to solve AI’s nondeterminism problem.

A Familiar Name in a New Chapter

This isn’t the first time Tulloch’s name has surfaced in connection with Meta. As we previously reported Mark Zuckerberg’s AI recruiting blitz included a reported eye-popping $1.5 billion compensation offer to lure Tulloch personally, possibly the largest in tech history.

At the time, Meta denied the specifics of the report, but the scale of the effort underscored how fiercely the company is competing for senior AI talent. Tulloch’s move now seems to close that loop.

Context: A Record Raise, a Quiet Launch

Thinking Machines Labs, founded by mostly ex-OpenAI staff led by Mira Murati was viewed as one of the most ambitious new entrants in AI infrastructure. Its record-breaking seed round set off speculation about what kind of breakthrough it was pursuing.

That first product, revealed earlier this fall, turned out to be a software toolkit for tweaking and experimenting with AI models, a practical, technical solution that some market observers found underwhelming given the company’s scale and hype.

TheMarketAI.com Take

The AI talent wars are still raging, and Tulloch’s move is proof that top engineers remain the most valuable currency in the industry. Meta, in particular, continues to pull aggressively from independent AI startups as it races to strengthen its foundation models and research infrastructure.

For Thinking Machines Labs, Tulloch’s departure is a test of stability following an extraordinary early trajectory. Its challenge now is execution, proving that its enormous funding round can translate into technological breakthroughs rather than just headlines.

And for the broader market, the message is clear: the poaching era isn’t over, it’s just getting more expensive. We put below a list of the original founding members of Thinking Machines Labs. Who else here is on Meta's poach list? Thinking Machines founding team (source: https://thinkingmachines.ai).

Name	Bio
Alex Gartrell	Former Leader of Server Operating Systems at Meta, expert in Linux kernel, networking, and containerization.
Alexander Kirillov	Co-creator of Advanced Voice Mode at OpenAI and Segment Anything Model (SAM) at Meta AI, previously multimodal post-training lead at OpenAI.
Andrew Gu	Previously working on PyTorch and Llama pretraining efficiency.
Andrew Tulloch (Chief Architect)	ML systems research and engineering, previously at OpenAI and Meta. Moved back to Meta October 2025
Barret Zoph (CTO)	Formerly VP of Research (post-training) at OpenAI. Co-creator of ChatGPT.
Brydon Eastman	Formerly post-training research at OpenAI, specializing in human and synthetic data, model alignment and RL.
Chih-Kuan Yeh	Previously Building data for Google Gemini and Mistral AI.
Christian Gibson	Formerly infrastructure engineer at OpenAI, focused on supercomputers used in training frontier models.
Devendra Chaplot	Founding team member & Head of Multimodal Research at Mistral AI, co-creator of Mixtral and Pixtral. Expert in VLMs, RL, & Robotics.
Horace He	Interested in making both researchers and GPUs happy, formerly working on PyTorch Compilers at Meta, co-creator of FlexAttention/gpt-fast/torch.compile
Ian O'Connell	Infrastructure engineering, previously OpenAI, Netflix, Stripe.
Jacob Menick	ML researcher, led GPT-4o-mini at OpenAI, previously contributed to the creation of ChatGPT and deep generative models at DeepMind.
Joel Parish	Security generalist, helped ship and scale the first versions of ChatGPT at OpenAI.
John Schulman (Chief Scientist)	Pioneer of deep reinforcement learning and creator of PPO, cofounder of OpenAI, co-led ChatGPT and OpenAI post-training team.
Jonathan Lachman	Operations executive, former head of special projects at OpenAI and White House national security budget director.
Joshua Gross	Built product and research infrastructure at OpenAI, shaping ChatGPT's learning systems and GPU fleet; previously on product infra at Meta.
Kevin Button	Security engineer focused on infrastructure and data security, formerly at OpenAI.
Kurt Shuster	Reasoning at Google DeepMind, full-stack pre-training and inference at Character.AI, and fundamental dialogue research at Meta AI.
Kyle Luther	ML researcher, previously at OpenAI.
Lia Guy	Previously at OpenAI and DeepMind, working on model architecture research.
Lilian Weng	Formerly VP of Research (safety) at OpenAI. Author of Lil'Log.
Luke Carlson	Former ML Engineer in Apple's Machine Learning Research group, designed ML frameworks for model orchestration, speech generation, private federated learning, and image diffusion.
Luke Metz	Research scientist and engineer, previously at OpenAI and Google Brain. Co-creator of ChatGPT.
Mario Saltarelli	Former IT and Security leader at OpenAI.
Mark Jen	Generalist, most recently infra @ Meta.
Mianna Chen	Previously at OpenAI and Google DeepMind. Led advanced voice mode, 4o, 4o-mini, o1-preview, and o1-mini launches.
Mira Murati (CEO)	Former CTO of OpenAI, led OpenAI's research, product and safety.
Myle Ott	AI researcher, founding team at Character.AI, early LLM lead at Meta, creator of FSDP and fairseq.
Naman Goyal	Previously distributed training and scaling at FAIR and GenAI @Meta, most recently LLAMA pretraining.
Nikki Sommer	Formerly VP HRBP at OpenAI and Director, HRBP at Twitter.
Noah Shpak	ML Engineer, loves making data go vroom while GPUs go Brrr.
Pia Santos	Executive Operations Leader, previously at OpenAI.
Randall Lin	Previously babysitting ChatGPT at OpenAI and co-tech leading 'the Twitter algorithm' at X.
Rowan Zellers	Formerly at OpenAI, working on realtime multimodal posttraining.
Ruiqi Zhong	Passionate about human+AI collaboration, previously PhD at UC Berkeley, working on scalable oversight and explainability.
Sam Schoenholz	Led the reliable scaling team and GPT-4o optimization at OpenAI. Previously worked at the intersection between Statistical Physics & ML at Google Brain.
Sam Shleifer	Research engineer specializing in inference, previously at Character.AI, Google DeepMind, FAIR, HuggingFace.
Saurabh Garg	Researcher, formerly working on all things multimodal at Mistral AI. Deep into the magic of pretraining data and loving every byte of it!
Shaojie Bai	Avid ML researcher to make audio-visual models better and faster, previously at Meta.
Stephen Roller	Previously full-stack pre-training at DeepMind, CharacterAI, and MetaAI.
Yifu Wang	Passionate about novel ways of overlapping/fusing GPU compute and communication. Formerly PyTorch @ Meta.
Yinghai Lu	ML system engineer, formerly led various inference efforts at OpenAI and Meta.