# Anthropic rewrites its Messages API backend in Rust using Claude

> Original title: its true, Anthropic really vibecoded their entire backend to Rust and none of you noticed

- Source: swyx
- Published: 2026-10-30T23:05:31.000Z
- Bad Influence: https://badinfluence.news/items/zv6ixd1kn2mzx9jg127yaj419
- Original: https://x.com/swyx/status/2116305528330785190

## Summary

Swyx says Anthropic rewrote its entire backend in Rust without noticing, citing a post from @somi_ai. The post says Claude wrote the code, the team had no Rust developers, and CPU use dropped 40-50%. Humans wrote the plan and checked the old and new systems matched on real traffic.

## Post

its true, Anthropic really vibecoded their entire backend to Rust and none of you noticed

## Quoted post @somi_ai

> Anthropic rewrote its Messages API in Rust. Zero Rust devs on the team.
> 
> Claude wrote the code. Humans wrote the plan and checked old vs new matched on real traffic. CPU dropped 40-50%.
> 
> Pretty sure "never do the big rewrite" is dead advice.
> 
> @katelyn_lesse on @latentspacepod

https://x.com/somi_ai/status/2116050219989373170