He Initialization
# For ReLU / GELU activations
nn.init.kaiming_normal_(w, mode="fan_in", nonlinearity="relu")
# Equivalent: w ~ N(0, sqrt(2 / fan_in))
Why it matters: Variance-preserving across ReLU layers (ReLU kills half the activations, so ×2 to compensate). Xavier (÷fan_in) is for tanh/sigmoid and will underflow gradients in deep ReLU nets.