PeopleofSuperintelligence

Researcher

Lewis Tunstall

Lewis Tunstall is a machine learning researcher whose work helps teams train and align open language models. He holds a PhD in theoretical physics and has held research posts in Australia, the USA, and Switzerland. He coauthored a practical Transformers guide and Zephyr-7B, then joined Numina’s team, whose NuminaMath system won the first AIMO progress prize in 2024. He is a Senior Research Scientist at Hugging Face and leads its post-training team.

Timeline

  1. 2010

    A Fulbright scholarship

    He becomes a Fulbright Scholar in 2010.

  2. 2016

    At the University of Bern

    A researcher at the University of Bern, he visits Edinburgh’s Higgs Centre in 2016 and presents a seminar on chiral-scale perturbation theory and the renormalization group.

  3. 2018–2022

    Transformers in Switzerland

    In 2018, he works with Transformers at a Swiss startup on question answering. By 2022, he contributes model-export tools for faster inference at Hugging Face and helps create the free Hugging Face Course.

  4. 2022

    A guide to Transformers

    In 2022, he coauthors Natural Language Processing with Transformers with Leandro von Werra and Thomas Wolf, a practical guide to training and scaling models with Hugging Face Transformers.

  5. 2023

    Zephyr-7B alignment

    In 2023, he coauthors Zephyr: Direct Distillation of LM Alignment. Its authors use AI feedback and distilled direct preference optimization to train Zephyr-7B; the paper reports state-of-the-art chat benchmarks among 7B models.

  6. By 2024

    A PhD and research posts

    By 2024, he holds a PhD in theoretical physics and has held research posts in Australia, the USA, and Switzerland.

  7. 2024

    The first AIMO progress prize

    Early in 2024, he joins Numina’s team with Edward Beeching to compete in the first AIMO progress prize. NuminaMath 7B TIR wins the 2024 prize and solves 29 of 50 problems on the private test set.

  8. As of October 2026

    Leading Hugging Face post-training

    As of October 2026, he is a Senior Research Scientist at Hugging Face and leads the post-training team, which develops fully open models, datasets, and training recipes.

Career

  1. NowHugging FaceSenior Research Scientist; Post-Training Team Lead
  2. From 2024Numina
  3. From 2016University of BernResearcher

From the biography.

  1. Google alumni have founded or led 133 other organizations, more than any other AI labIncludes Hugging Face. We estimate that alumni of 17 major AI labs went on to found or lead 350 other organizations, including 226 they founded, and we trace 472 career moves directly between 23 labs since 2010.
  2. The company share of AI researchers’ top papers was 31% in 2020–2024 and 8% in 1970–1974Includes Hugging Face. We estimate where the people shaping AI worked when their most-cited papers appeared: the company share was 31% in 2020–2024 and 8% in 1970–1974, and Google led all organizations in 2020–2024.
  3. Google has the highest combined h-index among AI organizationsIncludes Hugging Face. We estimate that Google holds the highest combined h-index at 8,016, while universities account for 73% of the deduplicated total across AI organizations.
  4. Companies supply the most prior-work hires at 7 of the 9 frontier AI labsIncludes Hugging Face. Our estimates of the organizations where 550 people worked directly before joining 9 frontier AI labs across 620 career transitions, comparing the main feeder organizations per lab.

Colleagues

People named in this biography, and people with dated positions at the same organization in the same years.

Sources and credits

Photo: We have no published photo of Lewis Tunstall yet. Send us a free-licensed photo.

  1. The Sequence Chat: Lewis Tunstall, Hugging Face, On Building the Model that Won the AI Math Olympiad thesequence.substack.com. Checked 20 October 2026.
  2. Chiral-scale perturbation theory and the renormalization group ph.ed.ac.uk. Checked 20 October 2026.
  3. Machine Learning Experts - Lewis Tunstall huggingface.co. Checked 20 October 2026.
  4. Natural Language Processing with Transformers - Google Books books.google.co.id. Checked 20 October 2026.
  5. Zephyr: Direct Distillation of LM Alignment arxiv.org. Checked 20 October 2026.
  6. How NuminaMath Won the 1st AIMO Progress Prize huggingface.co. Checked 20 October 2026.
  7. Dr. Lewis Tunstall – CERN STEAM Academy steamacademy.web.cern.ch. Checked 20 October 2026.