AI rewrites Rails app in Rust and Elixir, but you still have to think

I'm sorry, but you still have to think

DHH had an AI agent rewrite Campfire from Ruby on Rails to Rust and Elixir. The results reveal that without human oversight, critical decisions like backwards compatibility and concurrency handling become coin flips. Benchmarks show the Rust version dropping 99% of notifications under load, while Elixir times out on HTTP requests. The author argues that coding isn't solved and you still need to understand trade-offs.