DHH, AI Agents, and the Future of Ruby on Rails

Summary

FastRuby.io’s account of Rails World 2026 says DHH’s opening keynote focused largely on AI agents rather than Rails itself. He said 37signals had stopped writing code by hand, described HEY’s move to native apps with a Rust backend, and argued that Rails’ conventions and the web remain well suited to agent-assisted development. DHH also discussed Rails Foundation agent evaluations and said he had retired as a professional programmer. In a following panel, Matz said he had been coding with Claude Code since November and described Spinel, an ahead-of-time Ruby compiler whose tests reportedly used about one twentieth of the memory for a real-world program. Both speakers argued that Ruby remains valuable for explaining concepts even if humans write less code, while Matz warned that invisible infrastructure such as Ruby, Rails, Linux, and PostgreSQL could lose maintainers as agents take over more implementation work. The author agrees that agents can help understand legacy Rails code, but argues that people still need to read, review, operate, and make business judgments about what they deploy. The article also notes that Rails 8.2 had not yet shipped, although Herb had entered Rails core and Hot Cell’s Active Storage gems were awaiting the release. It closes by highlighting ongoing work on Lexxy, Herb, ReActionView, RubyGems security, Hot Cell, Ractors, and Rails performance as the technical future the author finds most compelling.