DHH’s AI Port of Campfire Reopens the Speed-vs-Readability Debate as Rust Benchmarks Draw Scrutiny

David Heinemeier Hansson, the creator of Rails, has revived a familiar programming-language argument with a new twist: what matters most when AI is writing more of the code. DHH said he had AI port 37signals’ chat app Campfire into Rust, Go, and Elixir, with early tests showing the Rust version handling about 36,000 chat page requests per second versus roughly 240 for the original Ruby implementation. That result pushed him to reconsider a long-held preference for Ruby’s developer productivity and readability. Vercel CEO Guillermo Rauch backed that line of thinking and pointed to Vercel’s own experience migrating roughly 70,000 lines of Go in Turborepo to Rust over 15 months. Even though the team saw Rust as a better fit for low-level systems work, the manual migration cost was high enough to spark internal debate over return on investment. The benchmark quickly came under criticism. Elixir creator José Valim said the compared versions were not equally optimized and did not share the same architecture. He noted that the Rust version had gone through hundreds of commits and several rounds of tuning, while the Elixir version remained close to its initial port. DHH replied that if top AI agents could not discover Elixir optimizations, that limitation also mattered in real-world development. An updated unified test on Oct. 8 showed Rust at about 106,000 requests per second and Go at about 53,000.