Anthropic rethinks source control

Anthropic says its software development bottleneck shifted from writing code to the systems around it, especially source control. The company reports that daily code merges grew from around 2,500 in May 2026 to more than 30,000 in September. To handle the increase, it built Scion, an in-house version control system, and migrated its monorepo from Git in five months.

Git’s decentralized model gives each clone a complete, self-contained repository, which works well for most repositories. It also offers tools for working with only part of a repository. Anthropic says its repository had grown large enough that its Git setup was becoming difficult to operate at its scale. Scion instead relies on a server for tasks such as history queries and merges, while clients fetch data as needed. Its design also supports sparse checkouts, so a job can work with only the files it needs. Anthropic describes the system and its design choices in its engineering post.

Most businesses won’t need to replace Git based on this example. Anthropic says Scion is designed for enormous monorepos and isn’t a suitable replacement for Git in general use. But it’s a useful signal: as AI tools increase the volume of code being produced, the surrounding systems may become a constraint before coding does. The post drew 200 points and 157 comments on Hacker News, another sign that the question is getting attention beyond Anthropic.