This. I've been marking undergrad assignments, and you would not believe how many sets and sorted sets I've seen implemented by linear scan over an unsorted arr

This. I've been marking undergrad assignments, and you would not believe how many sets and sorted sets I've seen implemented by linear scan over an unsorted array (or linear scan over a sorted array with linear time insert, and a few other, worse things). This lack of understanding of algorithms leads to slow, unscalable solutions, and even writing business middleware you at least need to know which standard library collections to use for good performance.