Fast forward to now. I'm a Buffett nerd — big believer in compound interest as a mental model for life. I run compound interest calculations constantly. Not because I need to, but because watching numbers grow over 30-40 years keeps me patient when markets get wild. It's basically meditation for long-term investors.

The problem? Every compound interest calculator online is terrible. Ugly interfaces, ads covering half the screen, can't customize compounding frequency properly, no year-by-year breakdowns. I've tried so many. They all suck.

When vibe coding started blowing up, something clicked. Maybe I could actually build the calculators I wanted? I don't have to be a "real developer" anymore — I just need to describe what I want clearly.

So I tried it.

Two weeks and ~$100（Opus 4.5 thinking model） in API costs later: I somehow have 60+ calculators. Started with compound interest, naturally. Then thought "well, while I'm here..." and added mortgage, loan amortization, savings goals, retirement projections. Then it spiraled — BMI calculator, timezone converter, regex tester. Oops.

The AI (I'm using Claude via Windsurf) handled the grunt work beautifully. I'd describe exactly what I wanted — "compound interest calculator with monthly/quarterly/yearly options, year-by-year breakdown table, recurring contribution support" — and it delivered. With validation, nice components, even tests.

What I realized: my years away from coding weren't wasted. I still understood architecture, I still knew what good UX looked like, I still had domain expertise (financial math). I just couldn't type it all out efficiently. AI filled that gap perfectly.

Vibe coding didn't make me a 10x engineer. But it gave me permission to build again. Ideas I've had for years suddenly feel achievable. That's honestly the bigger win for me.

Stack: Next.js, React, TailwindCSS, shadcn/ui, four languages (EN/DE/FR/JA). The AI picked most of this when I said "modern and clean."

Site's live at https://calquio.com . The compound interest calculator is still my favorite page — finally exactly what I wanted.

Curious if others have similar stories. Anyone else come back to building after stepping away?