Anthropic ported its Messages API from Python to Rust with a team that initially had no Rust deve...

Anthropic successfully ported its Messages API from Python to Rust using an engineering team with no prior Rust experience, utilizing Claude to handle most of the implementation. According to platform engineering head Katelyn Lesse, the migration resulted in 40 to 50 percent lower CPU usage and a 10 to 20 percent improvement in time to first token. The team ran shadow traffic in parallel and deliberately avoided adding new features during the rewrite. Open article →