> personalized feedback, quickly identifying where you are stuck and focusing the explanations and exercises on that area, This has been a huge blocker when I

> personalized feedback, quickly identifying where you are stuck and focusing the explanations and exercises on that area, This has been a huge blocker when I tried to study advanced math myself. Many of the exercise books don't have worked out answers, so often you're either stuck or you have to hunt a variety of sources online for solutions and advice. It kills flow.