37signals now treats hand-written code as a bug to trace back to its agents

I think the part of this policy worth copying is how it routes failures. Each hand edit becomes a defect report against the agent setup. 37signals did not ban hand-coding. A few weeks before the keynote it took hand-coding out of normal work and made it the exception ^[1]. A person who has to edit code fixes the few lines. Then they work out why the agent could not produce what was wanted, and fix the "factory" that makes the code ^[2].

His slides put his output at 647,000 lines over 21 years before agents and 321,000 in the 20 months since ^[7]. That works out to about 2,570 lines a month before and about 16,000 after, roughly six times as many ^[1]. August 2026 alone came to about 150,000 lines ^[8]. That one month is about 47% of the agent-era total ^[2]. Most of it is verbose Rust that DHH has said he does not read ^[9].

The language mix on the same slide is harder to dismiss. Ruby was 55% of his code across 21 years and 3% across the last 20 months, and he now uses 12 languages every day ^[10]. He said he built a calculator for Omarchy with seven minutes of prompting, knowing neither C++ nor Qt ^[11]. A reviewer of the keynote, writing on dev.to, found that more persuasive than the line counts because it shows how much one person can now work on ^[12].

The Rust backend follows from not reading the output. DHH calls Rust inhuman for people to write. His argument is that fast, light Rust is perfect when nobody has to read it ^[13]. The HEY apps he showed on stage had been kicked off about a week earlier ^[4]. His mail-server savings are an estimate on HEY's own workload ^[14]. For them to hold at another company, that company's mail service would have to be spending nearly all its CPU on work a Rust rewrite removes. "English is a better programming language than Ruby," he said ^[5].

DHH judges quality from outside, as a black box. He compared this to a business owner assessing the work of a development team they hired ^[16]. The reviewer's objection is that a hired team reads its own code, and someone on that team opens it when something breaks overnight ^[17]. On Basecamp 5, DHH said going back to manual review was the wrong call and the team should have waited for Fable ^[18]. The reviewer's notes do not show that work being rerun on Fable ^[18].

The case against abstraction is an odd one to hear from the creator of Ruby on Rails, a framework that has long put DRY first ^[15]. Agents, he argued, push the cost of duplicating code and keeping the copies in sync toward zero. With hundreds to tens of thousands of processes editing code at once, a shared abstraction becomes the bottleneck ^[19]. He said there is no blueprint yet, and that methodology and cycle length need rethinking too ^[20]. He also predicted that by year-end, writing code by hand will stop making economic sense in almost every domain ^[21].