Overall, this repository should help you learn some concepts but don't assume at any point that your interview will consist of questions included in this repository.
* Participate - there are great DevOps communities. I especially like [Reddit DevOps](https://www.reddit.com/r/devops). Visiting there, I learn quite a lot on different topics.
* Share - This is one of the reasons I created this project. Primary goal was to help others but a secondary goal quickly became to learn more. By asking questions, you actually learn better a certain topic. Try it out, take a certain subject and try to come up with questions you would ask someone to test his/her skills.
Well, from everywhere - past experience, colleagues, contributors, ... but please note we do not allow copying interview questions from interview questions sites to here. There are people who worked hard on adding those to their sites and we respect that.
It's a hard question and the reason is that if you'll ask 20 different people, you'll probably get at least 10 different answers but here is what I believe is common today:
* OS - DevOps require you good understanding of operating system concepts. The level required is mainly depends on the company although in my opinion it should be the same level. You should understand how the operating system works, how to troubleshoot and debug issues, etc.
* Programming is part of DevOps. The level again depends on the company. Some will require you to know basic level of scripting while others deep understanding of common algorithms, data structure, design patterns etc.
* Cloud and Containers - while not 100% must in all companies/positions, this skill is on the rise every year and many (if not most) of the positions/companies require this skill. This specifically means: AWS/Azure/GCP, Docker/Podman, Kubernetes, ...
* CI/CD - Be able to to answer questions like "Why do we need CI/CD?" and "What ways and models are there to perform CI/CD?". Eventually, practice assembling such processes and workflow, using whatever tools you feel comfortable with.
If you don't like some of the questions or think that some questions should be removed you can open an issue or submit a PR and we can discuss it there. We don't have rules against deleting questions (for now :P)
Same goes for copying questions from different sources to this repository. We saw it happened already with a couple of pull requests and we rejected them. We will not merge pull requests with copied questions and answers from other sources.
In most cases, I prefer questions added to this repository will have certain educational value for the user. Either regarding a certain concept or even a very general question, but one that will make you research on a certain topic and will make you more familiar with it.
I see little to none value in what is known as "Installation Questions". Let's say I ask you "how to install Jenkins?". Should I conclude from your answer that you are familiar with Jenkins? Is there a value in knowing how to install Jenkins? In my opinion, no.
You are right, both ask about horizontal scaling but first of all but, it's done from a different angel every time and in addition, I do believe repetition helps you to learn something better in a way where you are not fixed on one way it's asked.
