Rails originator roasted over Rust boosterism

Ruby on Rails founder David Heinemeier Hansson made a bold claim at Rails World 2026, suggesting that artificial intelligence could make manual coding obsolete. However, Hansson may need to reconsider his stance after sharing a test showcasing the performance of AI-generated code in three programming languages: Elixir, Go, and Rust.

Hansson compared the runtime speed of the same chat application written in each language, with the Rust version seemingly outperforming the others. The data appeared to validate the efficiency of Rust, as well as the capabilities of AI agents in coding. However, many observers quickly pointed out potential flaws in Hansson's benchmarks, suggesting he may have optimized the Rust results while neglecting the same level of optimization for the other languages.

The Rust rewrite of the chat app demonstrated impressive performance, handling 36,260 requests per second compared to Ruby on Rails' 241 requests and Elixir's 722 requests. Rust also excelled in the other tasks tested, often significantly outpacing the other languages. Hansson concluded that rewriting an application in Rust or having AI agents handle the coding may lead to major performance improvements.

Despite the Rust results, many observers criticized Hansson's methodology, arguing that he failed to apply the same level of optimization to the other languages. Critics pointed out that the Rust implementation received more post-coding attention than the Go and Elixir versions, raising questions about the fairness of his benchmark. Some even rewrote the Elixir code to match Rust's performance, revealing that the initial results were not as definitive as they initially seemed.