Do not call yourself a fair interviewing panel, if you ASSUME people are going to look at glassdoor for your interview question and prepare for it. Change your question to be ACTUALLY a FAIR and JUST company to hire a potential engineer. If you're going to be tossing the coin and assuming someone saw the question and prepared, that's the heights of unfairness and biased interview and people operations panel ever seen. Either don't call yourself unbiased or least change questions instead of rejecting someone without any base. Many engineers can have the same thought process and also could have quick grasping power. Most prejudiced company ever.