The creator of Jujutsu has joined ERSC
Martin von Zweigbergk, creator of the popular Git-compatible VCS Jujutsu (JJ), has joined East River Source Control (ERSC) as CTO. This move signals ERSC's intent to build next-generation version control solutions specifically designed for the challenges of AI-driven development and massive monorepos. The announcement sparked extensive discussion among Hacker News users, dissecting JJ's value proposition against Git and questioning the future of open-source JJ within a corporate venture.
The Lowdown
East River Source Control (ERSC), a company founded in 2025 and backed by Amplify Partners, has announced that Martin von Zweigbergk, the creator of the Jujutsu (JJ) version control system, has joined as Chief Technology Officer. This strategic hire aims to leverage von Zweigbergk's decade-plus experience in large-scale source control, including his work on Git, Fig (a Mercurial client at Google), and JJ, to lead ERSC's engineering efforts.
- JJ's Origins & Status: Jujutsu began as a side project in late 2019, evolved into von Zweigbergk's full-time work at Google, boasts over 30,000 GitHub stars, and is Apache 2.0 licensed.
- ERSC's Mission: ERSC is focused on developing next-generation version control platforms to address the "exponentially increasing needs" of source code management and collaboration, driven by AI's impact on the software industry.
- Future of JJ: von Zweigbergk will continue to maintain JJ as an open-source project. ERSC storage, designed to complement JJ's client-side improvements by re-imagining the remote server layer beyond Git's limitations, will enter private beta soon.
- Industry Context: The company aims to solve "hard problems" faced by engineering teams, particularly those working with large-scale monorepos, a challenge Google and Meta encountered earlier.
This announcement positions ERSC as a significant player in evolving version control for the AI era and enterprise needs, with JJ serving as a key component of their strategy while maintaining its open-source integrity.
The Gossip
Jujutsu's Judicious Joys (and Jabs)
Commenters extensively debated the practical advantages of Jujutsu (JJ) over Git. Proponents lauded JJ's enhanced user experience, highlighting features like a comprehensive 'undo' mechanism, non-destructive editing, and simplified rebase and merge conflict resolution. They argued that JJ's transactional model makes complex version control operations intuitive, even for daily tasks. Skeptics questioned JJ's necessity for developers with simpler workflows, suggesting Git already suffices for their needs. However, many who tried JJ reported that its benefits extend beyond niche use cases, fundamentally changing their workflow for the better.
ERSC's Enterprise Endeavors
Many users sought clarification on East River Source Control's (ERSC) value proposition, questioning its differentiation from existing platforms like GitHub. ERSC representatives explained that the company is not building a social coding site but rather enterprise infrastructure tailored for large monorepos and AI-driven development. They emphasized tackling the fundamental limitations of Git's design (on-disk format, CLI, wire protocol) at scale, aiming to offer solutions for performance, security, and features like per-directory ACLs. ERSC plans a commercial, enterprise-focused business model with no free tier, targeting organizations encountering Git's ceiling.
Open Source Outlook & Operational Harmony
Concerns arose regarding the future of Jujutsu's open-source status following its creator's move to ERSC. Company and JJ maintainers reassured the community that JJ remains an independent, Apache 2.0 licensed open-source project, with Martin von Zweigbergk continuing his core maintenance. A key advantage highlighted was JJ's interoperability with Git; it uses Git's backend, allowing individual developers to use JJ locally while teammates continue with Git, thus sidestepping the 'network effect' barrier that hindered past VCS alternatives like Mercurial. The project's healthy community and governance structure were also underscored.