“The popular image of AI spewing code is almost backwards; at this scale, the work looked much more like iterative investigation, inspecting the current state, forming a hypothesis, making a targeted change, rinsing and repeating.”
430,000 lines of TypeScript went in and 800,000 lines of Rust came out. Nobody at Microsoft will read all of that. The speed and memory numbers look great, and they also shipped dozens of regressions the compiler was happy to approve. The $120K price tag leaves out the people who will spend years debugging code no human wrote.