OpenAI’s engineering team has built an internal beta software product with zero lines of manually written code, relying entirely on Codex agents to generate about a million lines of code over five months. This approach redefines engineering roles to focus on designing environments and feedback loops that enable agents to work effectively, with humans steering and agents executing. The system emphasizes repository knowledge as the single source of truth, agent legibility, and strict architectural constraints enforced mechanically to maintain coherence and high throughput.

Codex agents autonomously handle tasks from bug reproduction to code validation and merging, while human engineers provide high-level guidance and oversee the system. Ongoing challenges include managing architectural coherence over time and designing environments that maximize agent productivity.

Source: OpenAI Blog