&gt;Yes, people are really doing this. It&#x27;s stupid, but to not do so puts you at a competitive disadvantage against other candidates. Competition for programming jobs is fierce.<p>I&#x27;m suspecting that this is a &quot;Valley&quot; thing, would that be wrong?<p>&gt;It is not enough to be able to implement quicksort. One must have the algorithm thoroughly memorized so that it can be scrawled onto the whiteboard in one smooth motion of the dry-erase pen. If you pause to say &quot;hmm...&quot; while re-deriving quicksort on the spot, you will be branded as &quot;slow&quot; and obviously inferior to the candidate who spent three days bashing his&#x2F;her head against an algorithms textbook.<p>If someone has years of experience in this field, and a strong portfolio, why would they need to remember how to do quicksort? They probably haven&#x27;t done it since their university days. That shouldn&#x27;t even remotely be the focus of an interview for someone who has done real work in this industry.