Building a Neural Network from Scratch in Pure Java (No Libraries)
A complete, from-scratch implementation of a feedforward neural network in pure Java — no TensorFlow, no DL4J, no external libraries. Covers the Neuron model, forward propagation, sigmoid activation, backpropagation with gradient descent, and trains the network to learn the XOR function. Every line of code is annotated with the underlying mathematics so you understand exactly what the network is doing at each step.