How I Built a Free Python Practice Platform With Zero Server Costs Using Groq and Supabase

I wanted to build a Python coding challenge platform that generates a completely unique problem every single time. No question bank. No repetition. Genuinely infinite practice.

The challenge was cost. AI API calls cost money. If thousands of students use a tool daily, the API bill scales with them. Most free tools either cap usage or die when they hit their billing limit.

Here is how I built PyCodeIt with a Bring Your Own Key (BYOK) architecture that keeps server costs at zero while giving users a completely frictionless experience.

The Architecture

┌─────────────────────────────────┐