Cisco isn’t just using Codex as a fancy autocomplete tool—they’ve fully baked OpenAI’s AI into the core of how they build software. The results are eye-popping: over 95% of new AI features are now written by Codex, defect resolution is up 10-15x, and they’re saving 1,500+ engineering hours monthly. For AI Defense, Cisco’s big AI security product, Codex compressed work that usually takes multiple quarters down to just weeks. The real shift here? Codex acts like a full-fledged engineering teammate that can understand massive codebases, run autonomous compile-test-fix loops, and play nice with enterprise security and governance. Cisco even helped OpenAI tune Codex for the real world. Why it matters: This isn’t a toy demo—it’s a concrete blueprint showing that AI-native development isn’t just for startups, and it’s probably coming to an enterprise near you soon.