Why one neuron draws only straight lines and a hidden layer bends them, then backpropagation by hand, a slope engine you write yourself, and networks trained from scratch.
Free to start · adaptive placement finds your level · reviews timed to your own forgetting.
Every idea is taught with motivation and a worked example before the drills, and an FSRS spaced-repetition engine schedules each review for the day its model predicts you would forget it. A short placement check finds what you already know, so you start Machine Learning: Neural Networks from Scratch exactly where it's useful.