From Typing Code Letter by Letter to AI Agents: A Developer's 20-Year Shift

A software developer reflecting on two decades in the industry describes how coding has transformed from handwriting exam answers on paper to directing AI agents that generate code autonomously. The shift became vivid when a younger colleague asked whether he used to write code 'character by character' — a framing that had never occurred to him despite being the only way code was once produced. At Rails World in September 2026, DHH announced that 37signals has gone 'pencils down' on writing code by hand, treating manual coding as an exceptional state rather than standard practice. In a room full of Rails developers, only about five people raised their hands when asked if they still write significant amounts of code manually each week. The developer notes that while AI agents now produce most code, the industry is still adapting old structures — version control, code review, diffs — to this new reality, with many fundamental questions still unanswered.