Five
paths

Five directions through the same six levels: Algorithms, Statistics, Machine Learning, Signals & Control, and Python Fluency, which runs through the other four. You do not have to grow every leaf: each path names the required problems its lessons teach at every level, then picks one problem from each topic for you.
Your picks are your own, so they cannot be memorised. Finish both and you have shown you can solve problems you have never seen. Teaching a course? Assign a path in Canvas.