Pretty much a hard requirement if you want to interview at your MSFTs and AMZNs. However, aside from condensing everything into one location and forcing you to think of your own test cases (which is beneficial), I remain to be convinced that there's a HUGE amount of extra value over leetcode, geeksforgeeks etc. In either case, if you did 189 algorithms/design questions, you will probably pass that part of the interview. The terse language used can be jarring at times, because some of the descriptions do lack depth. I recommend the book, but to get the max benefit, I'd recommend having at least a cursory understanding of all the data structures and concepts, because this book is not a good introduction.