Andrew Tulloch

Andrew Tulloch grew up in Perth, Australia, and studied mathematics at the University of Sydney and the University of Cambridge before spending about 11 years at Facebook, later Meta, working on machine learning systems. Tulloch's name appears on "Accurate, Large Minibatch SGD: Training ImageNet in 1 Hour" (June 2017), the Facebook AI Research paper that trained a ResNet-50 image classifier on 256 GPUs in an hour by scaling the learning rate with the batch size, and on Meta's 2021 paper on the ZionEX system for training recommendation models across many machines.

A move to OpenAI followed in 2023, where by Tulloch's own account the work included training GPT-4o, GPT-4.5 and o3. In February 2025 Tulloch was among the co-founders of Mira Murati's Thinking Machines Lab. After Murati turned down an offer from Mark Zuckerberg to buy the company, the Wall Street Journal reported in August 2025, Meta approached individual staff, and the package offered to Tulloch could have reached 1.5 billion dollars over at least six years with bonuses and stock gains; Meta spokesperson Andy Stone called that description "inaccurate and ridiculous." The offer was turned down at first. In October 2025 Tulloch told Thinking Machines staff of a departure, which a company spokesperson explained as a decision "to pursue a different path for personal reasons," and moved to TBD Lab, the research group inside Meta Superintelligence Labs led by Alexandr Wang, describing the work as "working on superintelligence."

On 9 September 2026 Semafor reported that Tulloch was leaving Meta, having waited until the day after Meta launched its Muse models and assistant. The next day the Wall Street Journal reported that Tulloch would join Anthropic's inference and performance team. Neither company had confirmed the move when this profile was checked.