Discovered chain-of-thought prompting
Jason Wei
Profile
Jason Wei is one of a handful of researchers whose work directly shaped how modern LLMs think. At Google Brain, fresh out of Dartmouth, he was first author on three papers that any serious prompt engineer has already stood on the shoulders of: Chain-of-Thought Prompting, FLAN (instruction tuning), and Emergent Abilities of Large Language Models. Every time you ask a model to “think step by step” — or use any model fine-tuned to follow instructions — you’re downstream of his work.
In 2023 he joined OpenAI to work on reasoning and agents, and became a core contributor to the o1 model — the first major “think before answering” model, which baked chain-of-thought into training itself rather than leaving it as a prompting trick. In 2025 he left for Meta Superintelligence Labs, part of the widely reported wave of poaching that pulled several o1 contributors to Meta.
For developers, Wei matters because he’s one of the clearest thinkers about what works with LLMs and why. His blog posts on emergence, scaling, and prompting read like field notes from someone who actually ran the experiments — not hype, not hand-waving. If you want to understand why reasoning suddenly appeared at a certain scale, or why instruction tuning turned GPT-3 from impressive-but-weird into genuinely useful, his papers are where the answers live. He’s also surprisingly generous with writeups and talks — a researcher who explains, not just publishes.
Worth noting: along the way he co-authored Emergent Abilities with a cast that includes Jeff Dean, Percy Liang, and Oriol Vinyals — essentially a who’s-who of frontier LLM research circa 2022.
Key Articles & Papers
Chain-of-Thought Prompting Elicits Reasoning in Large Language Models Finetuned Language Models Are Zero-Shot Learners (FLAN) Emergent Abilities of Large Language Models 137 Emergent Abilities of Large Language Models (blog) Learning @ Test-Time Is the New Pretraining Common Arguments Regarding Emergent Abilities Introducing OpenAI o1Spotify Podcasts
