I couldn't afford ChatGPT, Claude, or any API subscription. I had a 5-year-old laptop with a 6GB GPU and 16GB of RAM. I had a PhD in Physics, a Lean Six Sigma Black Belt, and zero - literally zero - Python experience.
So I built my own.
Not from nothing. I had 20 years of coding in MATLAB. I knew how to think in code, just not this code. I had a PhD in Physics: first principles, elegant solutions, no brute force. A Lean Six Sigma Black Belt: every millisecond, every megabyte accounted for. And enough PM experience to treat a solo passion project like a product with a roadmap.
I didn't learn Python. I translated everything I already knew into it. DMADV from scratch: Define, Measure, Analyze, Design, Verify. Root cause every failure. Iterate without ego. Six months later, she was real.