The one question I got "wrong" in my last series of interviews was for cloud security engineering. The question was "If you're having a DDOS attack against your web server, what do you do?" I discussed the various ways to prevent the attack at the network layer, etc. The "correct" answer they were looking for was "Go wide, bring up more and more and more servers all behind a load balancer."

Now, I get what he was asking for. There are problems with that as the only answer, as you would still most likely have a single back end that would be crushed in that situation. But the job was for AWS, and they can charge more for each server you bring online...