AI news · October 14, 2026
Anthropic built Scion after code merges passed 30,000 per day
Anthropic says merges rose from 2,500 to over 30,000 per day; Scion made checkouts two orders faster, cut source-control CPU and memory needs 200x, and saved 25% of CI CPU capacity.
- daily merges in September
- 30,000+
- smaller reported footprint
- 200x
- reported CI CPU saving
- 25%
Anthropic says its main monorepo went from about 2,500 merged code changes per day in May to more than 30,000 in September. The history reached almost 100GB, a compressed working copy exceeded 25GB and CI ran about 25 million code checkouts per day. The company built Scion, a server-first source-control system, plus a review tool and search service, then moved the monorepo from Git in five months with a team of seven people.
Anthropic reports that Scion made CI and research checkouts two orders of magnitude faster, reduced its source-control CPU and memory footprint by 200x and delivered a 25% CI CPU capacity gain. This is not a reason for a normal team to replace Git. It is a warning that agent-heavy development can move the bottleneck into build, review and source access. Smaller teams should first measure checkout time, repeated repository reads, queue wait and review hours before adding a new service.
What you can do with it
Instrument your build and agent runs for checkout time, repository bytes read, queue wait, merge conflicts and review hours. If the same repository data is fetched repeatedly, try a bounded cache or API query on a test job. Keep Git for normal work until a measured bottleneck justifies a new source-control design.
Our take
Scion is a strong infrastructure case study because the pressure came from real work volume, not a speculative roadmap. The reported gains are internal and the migration cost was high. The portable idea is to measure the full development loop and remove the first repeated cost, rather than assuming a faster model will fix a slow repository.
Source: Anthropic — Made With Models writes the brief; the reporting is theirs.