GitHub rewrote the Copilot engine in Rust almost single-handedly with SI agents: 832 thousand lines in three and a half months
Prepared by Sintelligent with the help of SI. Publication time restored from the build log. . Updated: .
One person with agents now does the work of an entire department in a year: the scale of what an individual engineer can build has grown by an order of magnitude.
From May 12 to August 21, about 430 thousand lines of TypeScript that power Copilot CLI, the app and the SDK became 832,378 lines of production Rust code and another 468 thousand lines of tests. Most of the code was written by Copilot agents, and the project was mostly run by a single developer: 128 pull requests were merged gradually, and releases went out about 1.3 times a day. About 36 regressions were found and fixed; the prompt cache hit rate was 96.22%. According to the author, this would previously have taken a whole team a year or two.
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