Anthropic's platform engineering lead says Claude now writes "literally all" her team's code

Speaking at Grafana's ObservabilityCON, Katelyn Lesse said her roughly 200-person team, which runs Anthropic's core services and developer tools, no longer writes code by hand: engineers own system design and verification while Claude Code does the implementation, including a Python-to-Rust migration. Some test fixes already run with no human in the loop, and Anthropic is weighing letting agents change real codebases on their own.