Shi's AI Notebook

Mar 15, 2026 · Artificial Intelligence

How We Built a Full‑Scale Product Using Only Codex‑Generated Code

Over five months the team created an internally used product from an empty Git repository, writing every line of application logic, tests, CI configuration, documentation and tooling with OpenAI's Codex, achieving roughly one‑tenth the effort of manual coding while uncovering new engineering roles and processes.