I Built an App Entirely with Claude Code. This is What I Learnt

Across 26 calendar days, I logged 97 active hours and processed 9.9B tokens of Claude Code on a single project. The output is an app currently in production pilot, used daily by colleagues in real workflows. I built this in evenings and weekends, working around my day job. The 97-hour number deserves clarification. Most of it was Claude working autonomously while I watched the chat, dispatched the next thing, or stepped away to watch a video or work on something else with the window visible. My active attention was probably a quarter to a third of that.