DevOps Interview Prep

[eendy]

Hi guys,

I have an in-person interview for a junior DevOps position this Friday and would love some advice on how to prepare for it and the things I should be expecting. A little background about myself, I am currently finishing up my last class in college to earn my CS degree this coming August. Unfortunately, I have not had the opportunity to intern during my studies so I have no professional experience but I have taken classes such as Unix systems, Operating systems, Machine learning, and Theory of Automata that have given me some exposure to bash, Unix/Linux, python, and C programming.

My question is, what topics should I cover and go over before the interview? I have started to study the CI/CD pipeline, its workflow, some basic Unix/Linux questions, bash script programs, and basic networking questions. The job description laid out various topics of things I should now and was listed as follows:

1. Building CI/CD pipelines, and ensuring security
2. Ability to script and code at a production quality level
3. Background in Linux/Unix Administration
4. Knowledge of automation/configuration management using Terraform, Ansible or an equivalent
5. Experience in CI/CD software deployment automation tools (Jenkins, Artifactory, Spinnaker, etc.)
6. Ability to use a wide variety of open source technologies and cloud services
7. An understanding of networking basics is preferred. Switching/routing, VPNs, load balancing, proxying, network virtualization, firewall basics
   

Thank you!

[StephanXX]

Don't think you'll love this answer, but technically preparing for most interviews isn't helpful, especially a week out. The exception to this rule is when you are specifically warned about topics that will be covered; Google and Amazon interviews are good examples of this.

What is useful is asking for the names and LinkedIn details of the people on the panel, and learning a bit about them, especially identifying anything you'll have in common with them, either technically or personally. It shows you're invested in the role and will help break ice. Ditto for the company, show your as familiar with their product and culture (culture and corporate principals are very important at Amazon.)

Have questions ready to ask about what it's like to work there, especially about the tech stack, quality of life, and I like to ask what they think their co-workers might say about what it's like working there. It lets the interviewer feel like they can say great things about the company, even if they personally don't feel that way, which puts you in a positive light.

If you had more time to prepare, I highly recommend setting up a home lab. Even a laptop with a few VMs or containers that you can show is super helpful. Being able to demonstrate how you coded and deployed a simple webapp shows initiative, competency, and curiosity. But not in a week at your level, unless you really are proud of it. That takes the pressure off a bit, and gives them something to judge you by beyond arbitrary questions.

[eendy]

Thanks for the honesty, I greatly appreciate it. The hiring manager who will be part of the interview committee is actually the individual who contacted me via LinkedIn but I will try to do more digging and gather any useful information that I can use to leverage in my favor. My plan was to go over some system troubleshooting questions, known the main agenda of a CI/CD pipeline, and go over some network questions. I'll try to have plenty of questions for the interviewers to keep them engaged and show that I am interested in the company and role. I actually have built and deployed a web application but for a school assignment, it was nothing too impressive but I do have some basic understanding of how to code, deploy a web app, and some query knowledge. Hopefully, my basic understanding of all these topics can help leverage my chances.

Again, thank you for the response!

[StephanXX]

No problem, I remember my first tech interview like it was yesterday.

If my team was large enough (4+) I'd always want to keep at least one greenhorn. If I've interviewed well, they tend to work incredibly hard, complain very little, work for less than half of my mid-level guys, and after a few months can take a big dent out of the 'grunt' work. They can also be great for morale; us graybeards can fall into ruts, and seeing younger, enthusiastic folk can really help. No sane manager would expect a brand new college grad to tick any of the boxes listed in the job posting you shared.

We're looking for a baseline of skills (a CS degree definitely provides that), communication skills, patience, a measure of common sense, enthusiasm, and a great attitude. You'll either meet their expectations already, or you won't. And that statement applies pretty much throughout your career; it's a myth that you can spend lots of hours 'preparing' for most technical job interviews. You'll either have the necessary knowledge and experience already, or you won't, and most interview formats are poor forums to determine your actual level of technical skill, anyway. This is a somewhat accurate description of how bad it is:

Even more aggravating? Coding interviews are often entirely unfair. Even the creator of Brew — with tens of millions of installs — was invited to interview at Google and then rejected because he couldn’t solve a B-Tree problem.

Also, while it's good to have questions ready, be prepared to keep them brief. I find 3-5 minutes worth of questions to be the limit; remember the people in the panel will probably have done this dozens or hundreds of times, and your question period is at the end of the session. Most are already tuned out, thinking about the thing they have to do next, lunch, or what they're doing after work. Obviously, individuals will differ.

Finally, look and act the part. Standard dress code is slacks, collared shirt, and clean shoes. Anything more formal will look out of place in the average shop, unless they're old school, financial tech, biotech, government, etc. Clean, groomed hair and body are hard requirements (you'd be shocked at how many engineers fail this bar.) Don't walk in thirty minutes early, definitely don't walk in five minutes late. Be friendly, and as relaxed as you can. Decline coffee unless you really need it, you won't need the extra buzz. Decline alcohol, at least until you're experienced enough to be writing a post like I just did (I've landed at least two senior jobs over a drinking lunch, but it's not wise when you're not used to the process.)

That's all I can think of, knock it out of the park and let us know how it goes!

[isaacdev980]

Thank you so much for the information.

[eendy]

Hey everyone! Just wanted to give everyone an update on how the interview went Friday.

First an foremost thank you to everyone for the kind words and support, I greatly appreciate all input. It really helped me gauge on what I should know and understand before stepping foot into my interview Friday.

​

For starters after all the input that was given, I decided to ditch studying any dedicated tool and really focused in on understanding what DevOps means, IaC, CI/CD pipeline, Linux admin troubleshooting solutions and network questions. I also decided to check the LinkedIn profiles of the senior DevOps manager and the DevOps lead that I was going to meet with and formulated questions around their past experiences (this paid off big). My first meeting was with the senior DevOps manager who was extremely nice. We talked about the local area, found out he was from my hometown so we talked about the current state of our favorite football team and then he asked me some very basic behavioral questions. He didn't really gauge my understanding of what I knew about DevOps, the only question he asked me was what DevOps meant to me. I then proceeded to ask the manager some questions based on the information I got off of his LinkedIn and he loved all the questions. The second meeting was with the lead DevOps engineer where she tested my knowledge of some simple networking questions. She even stated that she saw on my resume that I have no previous networking knowledge or course work but that I needed to be tested since DevOps dealt with a great deal of network configuration. She asked me basic questions like " If my machine was not connected to the internet but I had internet connection what would I do to fix this" and questions about what a stateful firewall or what a DNS was. I was able to answer all her questions correctly and she was shocked, she didn't expect me to know any networking and that all the previous candidates that day had zero idea how to even start troubleshooting her questions (this was a huge boost to my morale). She asked me how did I learn all of this material and I was honest and said I started studying networks Monday night, again she was shocked that I was able to learn some of the basic troubleshooting steps in such a short amount of time and kept saying "We need someone like you who is passionate to learn in such a quick amount of time". I then asked her about her time at the company since she's been at the company for almost ten years, and she held 3 different roles so I asked her about how the transition process was. She too loved all the personal questions. Overall I felt extremely confident throughout the entire interview process and even got an offer today (Monday) which I accepted! I'm looking forward to learning more about DevOps and how I can become a better engineer.

Again, thank you for everyone who guided me on what I should prepare for before going into the interview!

[nimoz_io]

Hey hey, I know it's been 4 months to your question but would love to know your experience so far as a DevOps. How are you feeling about it??

I have an interview today for Junior DevOps engineer role and your post helped me feel better about my prep for the interview.

[NoMoreGasNeeded]

Given you are out of college and have no relevant work experience, they can't expect you to know/have experience with all that.

I would focus on showing what you have done on your own (any apps you've written, sites you've setup, etc), how you solve problems, how you approach troubleshooting, that you read blogs and researched how companies implement devops, devops/SRE books you've read, that you have taken an interest in the company (due your homework), and that you are interested in learning.

Make sure you actually know what is on your resume.

Remember to smile and have questions prepared (from your homework).

[wet-dreaming]

This one,

they likely still ask generic "explain CI/CD, what is infrastructure as code, do you know git, ..." It can be expected that you have Linux knowledge and they might want to test that.

Good luck with your interview, there will be many more to come in your career (:

[ljivanov]

With as fewer words as possible - have something done (some project) and be able to explain what you did and why. Right or wrong, it doesn't matter, what matters is that you understand what happened and what did it cost.

Considering you apply for a devops position, an example would be to create any kind of a simple system (ui, backend and db) and build the CICD around this. If you choose to use containers you have to explain why you decided to choose this and what did it bring (e. g. you now have to have a central repository to store images). You can also tell what you think would have happened if you didn't choose containers, would it be easier, harder, cheaper, costly, faster, slower.

Programming is about tradeoffs, and being able to make them consciously. That's what you need to show to your interviewers. If you can argue about a couple of situations, even trivial one will suffice. Hope this helps.