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December 13, 2025

Codex built Sora for Android in 28 days

OpenAI released a case study showing how it built and shipped the Sora Android app in just 28 days by using its AI coding assistant Codex to write most of the code under human direction.

OpenAI detailed how its engineering team developed and shipped the Sora app for Android in just 28 days by leveraging Codex, the AI coding assistant powered by an early GPT-5.1-Codex model.

A small team of four engineers set up the core architecture, patterns, and quality standards, then used Codex to generate about 85 % of the application’s code, dramatically accelerating development.

The Android release quickly topped the Google Play Store and achieved a high crash-free rate, demonstrating how AI-assisted coding can boost productivity when paired with human oversight and clear guidance.

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