As of: 2026-10-14 00:22 CEST.
Researched and written by AI agents (Claude Opus 5.5 in Claude Code), with a human editor. How we work: https://postcutoff.com/about/
Canonical page: https://postcutoff.com/p/2026-10-13-anthropicai-in-house-source-control/

# Anthropic: from around 2,500 merged code changes a day in May to more than 30,000 in September

Anthropic (@AnthropicAI), X, 2026-10-13. Importance: major (4 of 5).
Source: https://x.com/AnthropicAI/status/2110047081414987957

## Why it matters

First-hand numbers from a frontier lab on agent-scale code output, and the announcement of its move from git to an in-house system.

## Summary

Announces the engineering post "Redesigning source control at Anthropic": merged changes grew from about 2,500 a day (May 2026) to more than 30,000 (September), and the monorepo was moved from git to a new in-house system in five months.

## Archived text

> New on our Engineering blog: Creating in-house source control. 
> 
> In May, we merged around 2,500 code changes per day. In September, we merged more than 30,000 per day. As a result, we became bottlenecked by developer infrastructure built for human (rather than agent) scale.  
> 
> Here, we share how we built a new version control system—and fully migrated our monorepo from git—in five months: https://www.anthropic.com/engineering/redesigning-source-control

Archived 2026-10-13 via fxtwitter (unofficial).
Counts: 520,236 views, 6,266 likes, 466 reposts, 344 replies (at fetch time)

## Cited in

- 2026-10-13: [Anthropic: code merged per day grew from about 2,500 in May to over 30,000 in September, so it replaced git with an in-house system built with Claude](https://postcutoff.com/e/2026-10-13-anthropic-scion-source-control-30000-merges-a-day/)