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/BlakkMajik3000]

Platform engineer here, mainly devex.

You…probably should know those answers, even at the junior level.

Is this a bot trolling?

[u/WholeBet2788 → u/BlakkMajik3000]

I hope this is a troll. Even junior k8s with 1 year could answer these :-D

[u/Negative-Thinking → u/WholeBet2788]

Not really. People who only use managed EKS and AKS mostly never touch those things. On-premise is a different thing

[u/BlakkMajik3000 → u/Negative-Thinking]

I'd disagree. Before doing DevEx myself, I had to know a bit about "what lies beneath" even though we were using managed AKS.

It also doesn't help that OP themselves said they were a senior k8s engineer. So...🤷🏾‍♂️

[u/Low-Opening25 → u/BlakkMajik3000]

yeah but you can still totally manage GKE and to large extent EKS without knowing any of it, so there is probably lots of “engineers” that fall into this category.

[u/Negative-Thinking → u/Low-Opening25]

Exactly, just because you were exposed to it does not mean everyone who manages EKS clusters has to know each and every concept by heart, I surely don't and it never once was a problem in many years of managing multiple clusters with tens of services. Can I still call myself a senior engineer? If I will have a practical need for anything I don't know I will learn it on the job, otherwise it's just noise.

[u/WholeBet2788 → u/Negative-Thinking]

Are you really senior if you dont know difference between etcd and redis?

[u/Negative-Thinking → u/WholeBet2788]

Seniority is not defined by knowledge of every little thing. Sure, you might know what redis is. Etcd? EKS manages it for you, you don't even have to know about it. Noise. If you ever have to work with on premise, you will have to know about it, but learning this concept takes literally minutes. So it's a BS metric.

[u/WholeBet2788 → u/Negative-Thinking]

Yes, its not defined by knowledge of every little thing.

But if you claim to be senior in specific technology, which OP does, i expect you to know the technology in depth. An etcd question is not depth. If you go into official k8s website, its probably on first picture you will find...

Surely you dont believe that senior k8s engineers means you know how to upgrade cluster inside console and deploy application, right?

[u/Negative-Thinking → u/WholeBet2788]

You know what, you are right, if the title specifically says senior K8s engineer, then I agree.

[u/BlakkMajik3000 → u/Negative-Thinking]

Yep.

These are actually good questions because they test your understanding of both K8s AND distributed systems. I refuse to believe that in 2026 a senior ANYTHING wouldn't know what quorum is or how to explain how a web request works.🤷🏾‍♂️

The CNI stuff is, admittedly, outside my personal wheelhouse, but I have never claimed to even be a junior k8s engineer. I'm up front. I know how to build safe software delivery systems that your dev team won't hate. That's my value prop and I do a good job of keeping the interview questioning around that.

Because I swear before black Jesus that if someone asks me one more time to compare Flux vs ArgoCD, I'm going to rage quit DevOps/SRE. 🤬