OpenAI team shipped a product with zero lines of hand-written code
By Ryan Lopopolo (OpenAI)Built and shared by Ryan Lopopolo (OpenAI), not by me. Summarised from the public sources below. Check them before you rely on a number.
- Who
- Ryan Lopopolo (OpenAI)
- Category
- Software development
- Source
- YouTube · Web
- Dates
- Published 16 Apr 2026 · Found 17 Oct 2026
A small OpenAI team spent five months building and shipping an internal beta of a software product where Codex wrote every line of code. Engineer Ryan Lopopolo describes how the engineers' job became designing the environment, the rules and the feedback loops the agents work inside, which he calls harness engineering.
What they built
Three engineers, later seven, drove Codex agents from a structured Git repository. The agents wrote the code, tests and fixes and opened the pull requests themselves. The humans worked on architecture rules, context and feedback loops, so the agents could check and correct their own output instead of having a person write code.
The result
About 1,500 pull requests merged in five months, an average of 3.5 PRs per engineer per day, and roughly a million lines of code. OpenAI estimates it took about 1/10 of the time of writing the code by hand (self-reported).
Sources
Stripe's 'Minions' agents write more than 1,000 merged pull requests a week
By Stripe (Alistair Gray)
Stripe built its own coding agents, called Minions, that take a task from a Slack thread and deliver a pull request that passes CI and is ready for review. Each week more than a thousand merged PRs are written entirely by Minions; engineers review them but write none of the code.
Non-technical Meta PM builds and ships apps without writing code himself
By Zevi Arnovitz (Meta)
On Lenny's Podcast, Meta product manager Zevi Arnovitz shows his AI workflow, which lets a non-technical person build real products. He builds a new feature in his study app StudyMate live in the episode.
Claude Code's creator: 259 pull requests in 30 days, all written by AI
By Boris Cherny (Anthropic)
Boris Cherny, who started Claude Code as a side project at Anthropic, wrote on X that all of his code over 30 days had been written by Claude Code with Opus 4.5. The post became one of the most cited examples of agentic coding.
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