Anthropic says it migrated its monorepo from Git to Scion in five months to support code volume produced with Claude. The system assumes clients remain online: history queries, diffs and change creation run server-side, with sparse or on-demand working copies.
It reports more than 30,000 merged changes a day in September, up from roughly 2,500 in May. The architecture uses content-addressed storage, tiered caches and APIs that avoid some checkouts. Anthropic attributes roughly hundredfold faster checkouts and a 25% CI CPU-capacity saving to the design.
This is an internal architecture publication, not a public Scion product or a recommendation to replace Git. Anthropic emphasizes its unusual workload and token budget. Reported gains are not independent measurements or a small-repository promise.
Faster code production moves bottlenecks toward source control, testing and delivery.