David Heinemeier Hansson has told his engineers to stop writing code by hand.
At the Rails World keynote, the Ruby on Rails creator and 37signals figurehead said the company had gone “pencils down” on handwritten software. Writing code manually is now an “exceptional state”, reserved for the moments when an AI agent cannot produce what the team wants – and even then, the fix is to repair the machine rather than take over.
“This is a recognition of what is already happening,” he told the audience, before asking how many people in the room still wrote material amounts of code by hand each week.
The position is the most explicit version of a shift under way across the industry. Coding agents from OpenAI, Anthropic and Cursor have moved from autocomplete to executing multi-step tasks, and the debate has moved on from whether they help to how much human review they still need.
Not everyone agrees. In a Business Insider poll of more than 150 software engineers, about 45% described themselves as mainly keeping up with AI tooling, and 17.5% said they steered clear of AI code editors.
For startups, the practical question is what happens to the craft once the pencil is retired – and who is accountable when an agent ships a bug that nobody wrote.
