Kubernetes interview gone really bad

[u/MountainTruth6073]

I went to a kubernetes tech interview, expecting that they are going to ask me about my experience using kubernetes and some basic question or some system design about how I could possibly build a cluster some scratch but nop they end up asking me questions that I found it very difficult to answer from the top of my head:

- First warm up question was, Can you explain to me what it is Quorum?
- Next question, I guess it was a follow up question, Do you know what ETCD? What is the difference between ETCD and Redis?
- Next question, Given this CNI Flannel, Cilum and Calico, which one you will use and why?
- And the killer question that literally frozen me was explain to me under the hood what is happening when a user clicks a button to download a file.

As a Senior Kubernetes Engineer, it is realistic to know all this stuff from the top of my head? Does it makes sense?

I have the feeling that the interview was setting me to fail, I never have to have to memorize things in my career, I always have to understand and get into conclusion by reasoning. But this is the third interview where the interviewer expect me to know things by heart... I was in another interview where the interviewer asked me to name all of the type of kubernetes services and explain them, I forgot to mention the headless service which I never use in my life.

Maybe it is realistic, that is why I need to vent and have another point of view

[u/Fun_Protection5273]

You are venting about two different problems and its worth separating them.

Problem1: Some interviews do set unrealistic bars. Asking a senior engineer to name every service type including headless something you've never used in prod is a trivia test not competency assessment. That's a bad interview and you're right to be frustrated

Problem2: some of those questions are actually fair for a senior level. Quorum. etcd CNI tradeoff are things a senior engineer should be able to reason through confidently even if not from pure memory. And the background workings of the question what happens when user clicks a download button is all about checking whether you can think in systems.

The pattern you're describing suggests the gap is not technical know-how its more about how you perform when you are put on the spot. This is a very different problem to solve and the good news is it is completely solvable. Mock interviews under realistic pressure conditions close this gap faster than any amount of cramming tech docs.