A diamond has corners. A circle doesn't.
Why lasso (L1) can zero out a weight entirely while ridge (L2) never quite gets there, shown first as the geometry of the constraint region in weight space, then as a live curve fit on real, noisy data.
Regularization
Six optimizers walk into a bowl
SGD, Momentum, Nesterov, RMSProp, Adam and Prodigy, dropped from the same point on a real loss surface and raced to the bottom, live in your browser. First a clean bowl, then rougher terrain with false valleys.
Optimizers