How we used Codex to build Sora for Android in 28 days (openai.com)

In a remarkable showcase of AI capabilities, a lean engineering team launched the Sora Android app in just 28 days using Codex, the AI coding assistant from OpenAI. The app allows users to generate vivid videos from short prompts and became the top app in the Play Store on launch day. The rapid development relied on an early version of the GPT-5.1-Codex model, which enabled the team to focus more on architectural decisions rather than low-level coding, ultimately achieving a 99.9% crash-free rate. This project highlights significant advancements in the AI/ML community, demonstrating how tools like Codex can streamline software development. Codex could execute substantial portions of code efficiently while the engineering team maintained oversight on broader design choices and user experience. The collaborative workflow established an orchestra-like environment where Codex handled coding tasks, allowing developers to concentrate on higher-leverage activities. By emphasizing guidance and structured communication, the team effectively utilized Codex's strengths in understanding code and applying feedback, showcasing its potential to transform traditional development practices in creating robust applications efficiently.