How much did Stephen Toub's AI-driven Copilot Rust port cost in tokens and time?

Stephen Toub calculated from his session logs about 136 billion tokens, roughly $120,000 at the public prices OpenAI and Anthropic listed, before any discounts. His own time was about a fifth of 15 weeks, or around three weeks, since he ran other work in parallel. He had estimated 150,000 lines and six to eight weeks; the port grew to about 450,000 lines because of fast incoming code and logic moved down from the CLI.

• Toub said the same work done by hand would have needed a team for a year or two and would never have been approved.
• He compared the $120,000 bill with the yearly cost of one senior developer and said it was still a good deal.

Source: our own transcription of the episode. The full conversation is on Ryan Peterman (2026-11-02). Read the whole episode summary →

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