Nine engineers shipped Copilot Cowork globally in four and a half months
Microsoft says nine engineers took Copilot Cowork from an empty repository to worldwide general availability in about four and a half months, then moved its live runtime from Python to Rust. Agents wrote most of the code and examined every change, while engineers set the specs, architecture, security boundaries, and final judgment. The clearest scale marker is one day in which the team merged 1,211 backend pull requests without giving agents authority over what shipped.