Sam Altman · 2025-09-09
BlogSam Altman Honors Jakub Pachocki and Szymon Sidor
Authors: Sam Altman
Why it matters
Sam Altman publicly credits Jakub Pachocki and Szymon Sidor as foundational to OpenAI's success
Key claims
- Sam Altman publicly credits Jakub Pachocki and Szymon Sidor as foundational to OpenAI's success
- Jakub Pachocki is identified as OpenAI's chief scientist
- Pachocki and Sidor led the decision to scale reinforcement learning against conventional wisdom, producing the Dota result
- Pachocki led GPT-4 pretraining
Radar summary
Summary
In a personal blog post, Sam Altman praises two key OpenAI technical leaders, Jakub Pachocki and Szymon Sidor, calling them indispensable to the company's success. He credits them with repeatedly combining research and engineering to tackle problems that seemed impossible, noting that their work has not received sufficient public recognition. Altman describes them as a rare partnership that complements each other exceptionally well.
Altman outlines several major contributions from the pair: they decided to scale up reinforcement learning as a baseline despite conventional wisdom that it didn't scale, leading to the Dota result; they built much of the infrastructure enabling numerous scientific discoveries; Pachocki led GPT-4 pretraining; and together with Ilya and Lukasz, they drove the initial ideas behind OpenAI's reasoning breakthrough. Pachocki is identified as OpenAI's chief scientist, with Altman noting he once described Sidor as "indefatigable."
- Sam Altman publicly credits Jakub Pachocki and Szymon Sidor as foundational to OpenAI's success
- Jakub Pachocki is identified as OpenAI's chief scientist
- Pachocki and Sidor led the decision to scale reinforcement learning against conventional wisdom, producing the Dota result
- Pachocki led GPT-4 pretraining
- The pair, alongside Ilya and Lukasz, drove the initial ideas that led to OpenAI's reasoning breakthrough
- They built much of the infrastructure enabling OpenAI's scientific discoveries
- Altman describes their collaboration as a rare, complementary partnership
Source material
Full source text
AI has gotten remarkably better in recent years; ChatGPT can do amazing things that we take for granted.
This is as it should be, and is the story of human progress.
But behind the blinking circle, nicely abstracted away, is the greatest story of human ingenuity I have ever seen.
A lot of people have worked unbelievably hard to discover how to build something that most experts thought was impossible on this timeframe, and to build a company to deliver products at massive scale to let people benefit from it.
Most people who use ChatGPT will never think about the people that put so much work into it, which is totally ok, but just to take a minute of your time… There are two people I'd like to mention that OpenAI would not be OpenAI without: Jakub Pachocki and Szymon Sidor.
Time and again, they combine research and engineering to solve impossible problems.
They have not gotten enough public credit, but they decided to scale up RL as a baseline to see where it broke when the conventional wisdom was that it didn't scale which led to our Dota result, built much of the infrastructure that enabled a lot of our scientific discoveries, led GPT-4 pretraining, drove together with Ilya and Lukasz the initial ideas that led to the reasoning breakthrough, and have made significant progress exploring new paradigms.
Jakub is our chief scientist.
He once described Szymon as “indefatigable”, which is as perfect of a use of that word as I have ever heard.
OpenAI has not yet thrown a problem at them they have not been able to solve; I have heard about partnerships like there is research labs of the past where two people are able to complement each other so well, but it is very special to get to watch it unfold over the years.