Part 1 · Goldilocks
1 to 2 hours, browser only. Meet a neuron with a real job: get a patient's dose just right. Train it yourself with rotary knobs in a 3D brick clinic, then watch backprop turn the knobs for you.
start here →Part 2 · microGPT
Several hours, free Colab. The whole transformer, traced by hand: tokens, attention, and a working GPT small enough to read in one sitting. Ends with the Forbidden Fruit alignment game.
open the walkthrough →Part 3 · nanochat
Several hours, free Colab GPU. Train a chatbot that is genuinely yours, with checkpoints saved to your own Drive. Then talk to it.
train yours →