When AI Builds Itself
The Introduction uses this for the moment AI starts building more of itself; Chapter 26 returns to the same figures to show the pace of capability growth inside the company building Claude.
Cited in
Favaro, Marina, and Jack Clark. 'When AI Builds Itself.' Anthropic Institute, 4 June 2026. www.anthropic.com/institute/recursive-self-improvement. (80 percent of Anthropic's merged code written by Claude; engineers shipping roughly 8x more code per quarter, comparing 2021 to 2025.