Sergio Mattei
Sergio Mattei is a software engineer who has been a member of technical staff at OpenAI since 2026, working on Codex-related products; he previously worked at MicrosoftMicrosoftMicrosoft is a technology company founded by Bill Gates and Paul Allen in 1975 and headquartered in Redmond, Washington, with businesses spanning Windows, Microsoft 365, Azure, enterprise software, artificial intelligence, gaming and devices.Open the full entry and, as a student, founded community products for independent makers such as Makerlog.
Contents9 sections
Key facts
2017–2018Founding Taleship
According to his CV, he founded Taleship at age 17, a community project that brought writers together around turn-based gameplay.[1]
His CV also states that he was a world finalist in the Microsoft Imagine Cup in 2017, reaching the championship quarterfinals (top 32 worldwide).[1]
2018–2021Founding Makerlog and Cowork
According to his CV, between 2018 and 2021 he founded Makerlog, a community platform for independent creators that he says grew to more than 10,000 members and organized meetups; in the same period he also founded Cowork, a virtual coworking space for remote teams that launched shortly before the COVID-19 pandemic.[1]
His CV lists that he was named to Hacker Noon’s “20 under 20” in 2019 and appeared on the Indie Hackers podcast in 2020.[1]
2018–2023Studying at the University of Puerto Rico
According to his CV, he studied for a Bachelor of Science in computer science at the Universidad de Puerto Rico, Río Piedras, from 2018 to 2023.[1]
2022–2024Freelance Product Engineering
2024–2026Working at Microsoft
From 2024 to 2026, he was a software engineer at Microsoft, working on the user interface and user experience of Azure Monitor and on team developer tooling; according to his personal website, during this time he helped build and revitalize internal UI libraries and made upstream contributions to the Chromium project.[2]
2026Joining OpenAI to Work on Codex
Open-Source Projects
On GitHub he has published Opal, a small coding agent written in Elixir that can be used as a command-line tool or embedded in applications as an Elixir library, released under the MIT license.[4]
He also maintains acho.lol, an encyclopedia of Puerto Rican popular culture written in Markdown with Spanish and English versions.[5]
Related Organizations, Websites, and Public Accounts
Microsoft: Official website: https://www.microsoft.com/ (opens in a new window)[1]
OpenAI: Official website: https://openai.com/ (opens in a new window)[1]
Personal website: Public link: https://matteing.com/ (opens in a new window)[3]
X: Public account: https://x.com/matteing (opens in a new window)[3]
GitHub: Public account: https://github.com/matteing (opens in a new window)[2]