Dev adventures, epic bugs, tiny wins, and the occasional meltdown. Zola 2026-11-03T00:00:00+00:00 https://golden-fox.tech/tags/source-control/atom.xml 2026-11-03T00:00:00+00:00 2026-11-03T00:00:00+00:00 Aakriti Agarwal https://golden-fox.tech/til/scion/ <p>I read Anthropic’s article <a rel="external" href="https://www.anthropic.com/research/redesigning-source-control">Redesigning source control at Anthropic</a> and learned that Git had become a bottleneck once ai agents started writing and merging code much faster.</p> <p>To solve this, Anthropic built <strong>Scion</strong>, a centralised source control system and <strong>Antique</strong>, a code review tool. Unlike Git, Scion keeps the code history on a central server and only downloads files when they’re needed. The server also handles things like file history and <code>git blame</code> so clients don’t have to.</p> <p>For an easier overview with more industry context, such as how Google and Meta solved similar problems, read Gergely Orosz’s <a rel="external" href="https://blog.pragmaticengineer.com/the-pulse-anthropic-builds-its-own-source-control-system/">Anthropic builds its own source control system</a> in The Pragmatic Engineer.</p> <h2 id="the-controversy-giving-credit">The controversy: giving credit</h2> <p>The part I found most interesting was the criticism of Scion. Rain, an engineer who worked on Meta’s <strong>Mononoke</strong> (the server behind Meta’s <a rel="external" href="https://sapling-scm.com/">Sapling</a> source control), pointed out that many of Scion’s ideas already existed in Mononoke especially its <strong>Bonsai data model</strong> and <strong>derived data</strong>.</p> <p>Rain’s main issue wasn’t that Anthropic reused these ideas. It was that Anthropic’s original article didn’t credit the earlier work. After the criticism, Anthropic updated its article to credit Mononoke.</p> <p>To understand the criticism in more depth, read <a rel="external" href="https://typesanitizer.com/blog/scion.html">An outsider’s perspective on Scion and Mononoke</a> by typesanitizer, an engineer on Databricks’ source control team. They compare Scion with Mononoke and question some of Anthropic’s numbers. To see how other developers reacted, check out the <a rel="external" href="https://lobste.rs/s/s2qeww/outsider_s_perspective_on_scion_mononoke">Lobsters discussion</a> of that post.</p> <p>This stood out to me because reusing existing ideas is a normal part of software development. Still, I think it’s important to recognise the people who came up with them first especially when you present a new system as a major achievement.</p> <h2 id="what-i-learned">What I learned</h2> <ul> <li><strong>Git blame:</strong> Shows who last changed each line of code and when which helps developers understand a codebase’s history</li> <li><strong>AI creates new challenges:</strong> When code gets written faster tools like Git, CI and code review also need to keep up.</li> <li><strong>There’s more than one way to do source control:</strong> Git works well for offline development while centralised systems can suit always online AI agents better.</li> <li><strong>Giving credit matters:</strong> You don’t always have to invent something completely new but you should acknowledge the people whose work helped you.</li> <li><strong>Look at both sides:</strong> Reading the criticism alongside Anthropic’s article gave me a much better understanding of what happened.</li> </ul> <h2 id="my-main-takeaway">My main takeaway</h2> <p>This turned out to be more than a story about replacing Git. It also showed me how much credit matters in software engineering and building on other people’s ideas is completely normal but so is recognising their contributions.</p>