Braintrust, an observability platform for AI products, is using the Codex plugin with GPT-5.5 to radically speed up development. Instead of letting feature requests pile up in a backlog, engineers now paste customer ideas straight into Codex and get a working preview branch in minutes. That lets them show a live version to the customer right away and iterate together in real time. In just one month, half the team has switched to Codex. Founder Ankur Goyal says the sheer speed of the tool changes how he works—he can now write a test, spin up a sandbox, and let Codex solve the problem autonomously, rather than guiding it step by step. The faster output lets the team run more experiments and tighten the feedback loop with customers. Why it matters: This isn’t just about faster typing; it’s a shift from using AI as a coding assistant to using it as a collaborative development environment that compresses the entire build–test–learn cycle into minutes.