&gt; Someone who&#x27;s actively working through it will pause, they&#x27;ll hesitate, they&#x27;ll get things wrong and have to correct themselves.<p>Candidates who know the solution can and sometimes will do the same. Sure, you can try to catch candidates that try to fake it, but then the process becomes a cat and mouse game between the interviewer and candidate that distracts both parties from the real purpose of the interview, which is to find the most qualified candidate for a position.<p>None of this would be necessary if the interviewer simply used a lesser known question (or better yet, a more practical question adapted from something taken from the part of the codebase that they&#x27;d be working on) to begin with.