Contrast that to ML and even though I have done a large amount of work in it (in both university and in industry), I still can't fully appreciate how the building blocks interact to form an entire system. I find that I use intuition from other systems I have read about or implemented (e.g. decision trees and tabular data, ReLUs and images) to reason about the results in new systems and guess at better configurations and architectures.
Might say more about me, but I always found ML was a "start big and go backwards" deal whereas computer science was a "start small and go forwards" deal.