r/devops • u/MountainTruth6073 • 11d ago
Discussion Kubernetes interview gone really bad
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
4
u/tadamhicks 11d ago
I think in asking they’re trying to gauge how much you understand about the system. Quorum is something I’d expect a senior DevOps engineer to understand, yes. For k8s you should definitely know etcd and the role it plays. Maybe you don’t know all the fine points of raft but you should know what it is. And I’m going to guess they don’t care if you know Redis specifically but I’d expect you to know why etcd might be a better database than something else for kubernetes.
The CNI question I dunno…if I were interviewing you I’d hope you’d asking me some questions about ones you don’t have experience with that would show me that you understand what a CNI is and does and are capable of thinking about what critical capabilities differentiate each for different use cases.
The file download question is an old one. Another one is “what happens when you go to google in your browser?” That’s just gauging that you know how computing systems work in general. For those there’s often no 100% right answer…you could cover just the networking bits, the mem management, kernel modules, go to whatever depth…just display that you understand systems.
All this seems pretty brass tacks for me for a senior role.