从零手写 micrograd：神经网络与反向传播讲透

Andrej Karpathy's first Neural Networks: Zero to Hero lecture, which builds micrograd, a tiny autograd engine, from scratch in Python. It explains backpropagation and neural network training step by step, assuming only basic Python and some high-school calculus.

Why HN likes it: HN treats it as the best starting point for really understanding backprop and neural nets, because Karpathy explains the why with intuition and builds everything in code.

“It's especially useful because he explains the why and provides intuitive explanations instead of just talking about the what and how.”