In this video, I build a full Voice AI behavioral interview coach app in about 30 minutes using Next.js, Claude Code, and ElevenLabs. The app has a landing page, an interview page where you talk to an AI coach in real time, and a simple completion screen. The coach asks exactly five behavioral questions, gives brief feedback after each answer, and then switches to detailed feedback using the STAR method while also assessing soft skills like clarity, confidence, empathy, and leadership presence. The big takeaway is that most AI coding tools are “almost right, but not quite” — and the gap is the workflow. I walk you through five practices that made my Next.js builds faster and more reliable: scaffold with shadcn/ui create so the AI has UI guardrails, add a CLAUDE.md file for persistent project context, install skills for framework-specific best practices, use Plan Mode to separate thinking from building (and force the AI to ask questions before writing code), and commit checkpoints after every successful step so you can instantly recover when AI breaks something. If you follow this workflow, you’ll ship faster with fewer debugging loops.