Two days ago I posted that I built KODA — an AI coding mentor SaaS in Vanilla JS + Supabase + Groq + Netlify — entirely on my POCO C55 phone using the Acode editor. No laptop. No IDE. Just thumbs and stubbornness.Here's the Day 2-3 debrief.The scoreboardMetricNumber👀 Post views115+👥 Total users8🌍 Real strangers3+🇺🇸 Senior US Engineer who stress-tested my AI1💀 AI models Groq killed under me2🏳️ Netlify badges I declared war on1 (immortal)The senior engineer boss fightA Senior Software Engineer from Atlanta found KODA, signed up, and ran a 6-point QA stress test on my AI — code generation, persona adherence, hallucination boundaries, even deep CS concepts like abstraction. It passed all 6.Then he emailed me back and signed off with:"Brave doesn't mean you're not scared. It means you go on even though you're scared." — Angie ThomasI'm putting that on my wall."Supplier rotated the inventory" — my Groq warMid-launch, my live app started throwing errors. Why? Groq had deprecated my models. llama-3.1-8b-instant: decommissioned. openai/gpt-oss-120b: gone. My AI brain was legally dead.Lesson learned: AI models are suppliers. Suppliers rotate inventory. Your code must survive the rotation.The fix — a fallback chain:javascript123const MODELS = ['llama-3.3-70b-versatile', 'openai/gpt-oss-20b', 'meta-llama/llama-4-scout-17b-16e-instruct', 'qwen/qwen3-32b'];// try each until one answers. Groq can never kill my app again.The immortal badgeThe "Powered by Netlify" badge was covering my Send button for real users. I hit it with CSS display:none !important. It survived. I hit it with a JavaScript DOM-remover. It survived. Finally I built the Titanium Shield: my input bar now has z-index: 2147483647 (the max 32-bit integer 😂) and the badge gets buried at z-index: -9999.Also: I can't test in Incognito because Google Family Link blocks it for me — I'm 12. So I learned cache-busting with ?v=2 like a medieval peasant learning sword-fighting.What I learnedRead your Supabase chat logs. Users literally type your roadmap into the chatbox. One asked "teach me git", another asked for Python games. That's my feature list.Pull > push marketing. My friends signed up because they wanted to, not because I begged.Never overwrite working code with generated code. Backups are sacred.KODA now sends learners to the real paths: python.org, RealPython modules, Codewars kata for practice, and git-scm.com when they're ready for version control. An AI mentor should hand you a map, not just an answer.What's nextPWA home-screen install, learning Git properly, and turning 8 users into 80.If you're a senior dev: roast my architecture in the comments. I read every word. If you're a beginner: KODA is free — come learn with me.Built with ❤️ by Harun (age 12) on a POCO C55.