OpenAI: Braintrust Speeds Up Experiments with Codex and GPT-5.5

OpenAI published a customer story describing how the company Braintrust uses Codex in everyday development. Codex is OpenAI’s tool for generating code from natural language, and in this case it is powered by the GPT-5.5 model. The goal is to shorten the path from idea to a working implementation, especially in the experimentation phase.

How does Braintrust use the tool?

According to the story, Braintrust’s engineers rely on Codex to launch experiments and write code faster. Instead of manually translating requirements into an implementation, user requirements are turned directly into program code. This shortens the development cycle and reduces routine work, leaving more time for deciding on architecture and verifying the results.

Why does experiment speed matter?

In software development, experimentation means quickly trying out hypotheses, so every time saving is valuable. Launching experiments faster means more iterations in the same period, and therefore faster validation of ideas. This is especially useful for teams working on evaluation and measurement infrastructure, which is what Braintrust does.

What does this say about the trend?

The story fits into a broader trend in which advanced models become productive tools for engineers, rather than just an object of research. Turning requirements into code with GPT-5.5 shows how generative AI is increasingly integrated into real development processes.