That's a common way I see well-educated candidates fail our interviews. What happens is that they only have N minutes to do the whole interview... If they burn twenty minutes of that time gaming out whether the DB needs redundancy, multi-tier storage, and synchronization, they don't have time to actually show me the algorithm that will generate the data to go in the database, and that's what I'm hiring them for. "Is the database the right shape" is rarely a problem at our scale.
Some candidates also can get into this “word salad” mode, where they just talk and talk, and don’t listen to what you are saying. They have their script and talking points and just go on autopilot, filling every silence with words and words. You can give them obvious hints and cues: “Just give me the simplest answer and we will go from there!” …and they launch right back into 5 more minutes straight of talking.
As an interviewer, I have to manage our time appropriately so we can get into all the questions, and will sometimes even have to firmly say “STOP TALKING. Unfortunately we need to move on to the next question.”
