Codex clones Linear's core from a one-page spec in 3 minutes 28 seconds
aakashgupta · x · 2026-10-27
Prompted by Replit CEO Amjad Masad's claim that AI-powered reverse engineering will make all software de facto open source, the author ran a clean-room test: writing a one-page spec from Linear's public docs only, then handing it to Codex. In 3 minutes 28 seconds it produced a working issue tracker with 5 statuses, priorities, drag-and-drop and Cmd+K — even fixing its own failed self-check.
Context: Linear is valued at $2.5B with 40K+ organizations; in February someone cloned its core with 20 prompts. Adobe is down 26% over 12 months yet grew ARR 11% to $27.5B, and the open-source PhotoCraft rebuild went viral.
The key takeaway: a copy can match your screens but can't download your users — issue history, existing teammates, and integrations (GitHub, Slack, Figma, Sentry) are the real moat.
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