GitHub Chief Executive Thomas Dohmke is leaving one of the world’s largest software development platforms to start a new chapter as a founder. The news came Monday through a personal blog post, in which Dohmke reflected on his journey and explained that the pull toward building something from scratch was too strong to ignore.

“I’ve decided to leave GitHub to become a founder again,” he wrote, noting that his career began in the fast-moving world of startups and that he has long wanted to return to that environment. While Dohmke didn’t reveal the nature of his upcoming venture, the decision signals a major change both for him and for GitHub, which has been owned by Microsoft since 2018.

Dohmke’s career with Microsoft began more than a decade ago, when the tech giant acquired his mobile app startup. At Microsoft, he rose through the ranks, eventually leading mobile developer tools and working closely with then-CEO Nat Friedman to facilitate Microsoft’s $7.5 billion all-stock acquisition of GitHub. The deal brought the open-source platform, used by millions of developers worldwide, under Microsoft’s umbrella, a move that was initially met with scepticism in the developer community but has since helped GitHub expand its tools, services, and user base.

As CEO, Dohmke oversaw a transformative period for GitHub, including the integration of artificial intelligence into coding workflows through GitHub Copilot, which uses AI to help developers write code faster and more efficiently. He also pushed for greater accessibility, collaboration features, and security tools, solidifying GitHub’s position as an essential platform for programmers and organisations across the globe.

His departure leaves questions about the company’s next leadership phase. Microsoft has not yet named a successor, and the timing comes as competition in developer tools and AI-assisted coding intensifies. Still, GitHub remains a critical part of Microsoft’s developer ecosystem, with tens of millions of repositories and active users.

For Dohmke, the decision appears deeply personal. In his farewell note, he emphasised the thrill and creativity that come with launching something new, a feeling he says he’s ready to embrace again. While the specifics of his next project remain a mystery, his history suggests it will likely sit at the intersection of technology and innovation, and the tech world will be watching closely to see what he builds next.