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/smarzzz]

> As a Senior Kubernetes Engineer
I have some doubts about that

I might be too autistic to not understand this as a parody. But these questions are very basic Kubernetes platform engineering questions.

How do hell do you not know what quorum is?! Of the difference between ETCD and redis. Kubernetes 101 mate. Were you only a user, and never a hoster/supplier of this platform?

[u/BrocoLeeOnReddit → u/[deleted]]

Etcd and Redis are both key-value stores, with etcd being the default storage in K8s. It has more limited data types but is much faster.

Quorum basically means a voting majority when it comes to state, e.g. let's say you only have two servers and one goes down, then the two servers can't decide which is the correct state because both think it's their own. If you have 3 servers and one has a different state, the other two "outvote" it, that's what's called quorum.

[u/aenae → u/BrocoLeeOnReddit]

I think the main difference is transactions between etcd/redis, which is whe etcd is usually the default in k8

[u/PixelOrange → u/[deleted]]

Yes all of those things pertain to k8s.

I don't know that I could answer why I would use calico over cilium or vice versa. I think that's a preference thing or special use cases. I've never used flannel but the interwebs says it's more for simple setups.

Etcd vs redis is about how you store your data. That one is important.

[u/ccbur1 → u/PixelOrange]

I would vote for Cilium because of their great eBPF tech, Isovalents strategy and last but not least I had some good discussions with some of their engineers. Nevertheless the commercial products are not cheap, but enterprise ready.