Backpropagation: Which Way Should Each Knob Turn?
Training nudges billions of weights at once. Roll a weight down a loss curve, trace blame backwards through a network, and race SGD against Adam.
Pre-training: Learning Everything by Guessing the Next Word
Every LLM starts as random numbers, then guesses the next token trillions of times. Bet on the next token, train a tiny model live, and see why scale pays.