How Good Is GPT-5 Codex? I Built an App

Sign-up for updates to Verbi - transcription app: https://tally.so/r/3y9bb0 I put GPT-5 Codex to a real test: I handed it a PRD in VS Code, ran it with Codex CLI, and timed how long it took to build a working, on-device app. Watch the full build—planning → coding → debugging → demo—to see where GPT-5 Codex shines, where it stumbles, and if it’s ready for real projects. Website: https://engineerprompt.ai/ RAG Beyond Basics Course: https://prompt-s-site.thinkific.com/courses/rag Let's Connect: 🦾 Discord: https://discord.com/invite/t4eYQRUcXB ☕ Buy me a Coffee: https://ko-fi.com/promptengineering |🔴 Patreon: https://www.patreon.com/PromptEngineering 💼Consulting: https://calendly.com/engineerprompt/consulting-call 📧 Business Contact: engineerprompt@gmail.com Become Member: http://tinyurl.com/y5h28s6h 💻 Pre-configured localGPT VM: https://bit.ly/localGPT (use Code: PromptEngineering for 50% off). Signup for Newsletter, localgpt: https://tally.so/r/3y9bb0