Jenkins Interview Questions: From Basic to Expert

As DevOps-based work increases, so does the need for automated test systems and program development, such as selenium or jenkins. These job positions usually offer great benefits, such as expanded career opportunities and regular increases in income. It’s not uncommon for more and more people to choose this job position. However, to pass a job interview, everyone needs preparation. And what better thing to do to prepare than to study Jenkins interview questions?

In this tutorial, we’ll cover basic Jenkins interview questions and answers for experienced developers so you can get a thorough and insightful understanding of job interviews. We’ll see what Jenkins is, what it’s good for, and why people love it so much.

Introduction

Jenkins Interview Questions

Let’s get started and not waste our time by discussing the Jenkins interview questions that come up most frequently during job interviews.

Questions being “basic” are not unimportant, although when you fail, you may not get any profit. So, pay close attention and remember it well. Let’s start at the top.

Question 1: What is Jenkins?

Simply put, Jenkins is an open-source-based automation server, with continuous integration. Basically, if you’re a developer constantly creating new programs and software, but you’re not using Jenkins, you’re missing out and losing a lot of your time. Jenkins allows developers to test their programs on the go, all of which make it possible to integrate enhancements and additional features through the process.

Question 2: Why do developers use Jenkins?

As one of the introductory interview questions about Jenkins, your potential employer may want to examine what you consider to be the most important features of Jenkins. While the answer seems very subjective, here are some examples you might consider:

  • It’s easy to catch bugs early on;
  • Automated testing process;
  • Continuous integration.

Question 3: What is ‘automated testing?

One of the main (if not the main!) features that Jenkins is known for is its automated testing function. It’s easy to read this online and then just memorize the sentence only to have it said as an answer during one of Jenkins’ company interview questions. However, what if there was a follow-up to this? As a concept, automated testing has become so popular that it’s almost automatically considered (no pun intended) that everyone should know what it is.

Automated testing is when a particular program (framework) tests the developed program (web application) without the need for human intervention.

This is great for several reasons – a lot of money and time is saved, testing happens much faster, there is no room for man-made error. This is one of those interview questions about Jenkins that you should keep in mind!

Question 4: What is ‘continuous integration?

Another popular concept, especially if the job you are preparing with this Jenkins interview question is somehow related to the DevOps philosophy.

Continuous integration is a process when multiple tests are performed on a single project each day. This is done because there is usually more than one developer working on the project (program, application, etc.).

Question 5: What do you need to start using Jenkins?

There are two basic requirements to start using Jenkins – a decent source code repository and build scripts registered in that repository.

However, there are also two software requirements before you actually install Jenkins – Java Development Kit and Jakarta: Enterprise Edition.

Question 6: What is the default security mechanism for user authentication?

While at first glance this may seem like one of the more sophisticated Jenkins interview questions, it’s actually quite simple when you think about it.

You have several options to choose from when identifying a user, but the default function in Jenkins is to store user data in a database.

Question 7: Name at least two of the most popular plugins for Jenkin.

Maven and  Git are probably the two most popular Jenkins plugins today.

Question 8: How do you back up your files?

This is probably one of the few pretty self-explanatory Jenkins interview questions you might get.

The JENKINS-HOME directory contains all your personal configurations. This means that the only thing you need to do to keep your files safe and clean from any problems is to back up the directory.

Question 9: What is a ‘pipeline’?

The term ” pipeline ” is used to describe the process from the earliest stages of a project’s development to its public release.

Question 10: What are the three fundamental stages of the Jenkins pipeline?

Build the project, test the project and then deploy the project.

Advanced Jenkins Interview Questions

 

Those are ten examples of how the start of your Jenkins job interview might look. As you may have noticed, the questions are quite simple – they are designed to check your general knowledge of Jenkins, automation, DevOps, and so on.

Now that you know what to expect, we can move on to the Jenkins interview questions and answers for experienced developers and programmers. These questions and answers are designed to check how deeply you know the topic. Besides, when it comes to these interview questions about Jenkins, they’re not always super difficult – they’re just a lot more technical.

Question 11: How is Hudson’s relationship with Jenkins?

This is one of the more interesting Jenkins interview questions – it examines not only the technical research you’ve done on Jenkins, but also how deep you dig into the program’s history.

A long time ago, Hudson was the official name (an earlier version) of what is now known as Jenkins.

Question 12: Name two ways how you can schedule builds.

You can issue commits to source code management or, if you prefer, you can manually request a build.

Question 13: What are the most popular environment variables?

These types of Jenkins interview questions can be a bit difficult to solve, as employers may intentionally try to make the questions a lot more difficult than they need to be.

Given that the questions are most likely related to the work of building Jenkins, there are many elemental variables to choose from. Here are some of the more famous:

  • $JOB_NAME
  • $JOB_URL
  • $ WORKSPACE

Question 14: How do you move files from one server to another?

This is considered one of the advanced Jenkins interview questions mainly because there are several possible answers to it. However, if you want to keep it as simple as possible (which is highly recommended), there is a really easy answer – just copy the working directory and paste it on another server.

Question 15: Should you use Jenkins along with Selenium?

Yes, it’s actually quite advantageous – this type of combination runs live tests every time your program changes or is modified.

Question 16: What is the best way to ensure that your Jenkins database is secure?

There are many ways to ensure security is at the top level when it comes to Jenkins, but some of the more important ones include (but are not limited to) maintaining global security, running security checks, keeping your database protected on a physical level. (not allowing unauthorized personnel to approach it), etc.

Question 17: What is Possible?

Ansible is a configuration management tool that has the capability to be deployed for provisioning and can be implemented into Jenkins.

Question 18: What is an ‘agent’?

The ” agent ” can be seen as a reference point – it defines the point in the pipeline where Jenkins will launch.

Question 19: What is a ‘Jenkinsfile?

This is a text file that contains all the information about the project pipeline. It should always be implemented into source control.

Question 20: What is the command to start Jenkins manually?

jenkins.exe start

Job Interview Tips

So far, we’ve covered what Jenkins is, talked about the basics, and covered some of the main Jenkins interview questions and answers for experienced users. Now that you can imagine what to expect from a job interview, I want to cover some of the more general things you can do before, during, and after the interview.

Job Interview Tips: Before Interview

So – you’ve scheduled your interview, only a week left, and you’re ready to start preparing. There are many different things you can do to maximize your chances of actually getting the job.

First, develop a schedule for studying. And this doesn’t mean that you have to study 16 hours per day – many people think that if they do nothing but study and repeat all the time until the interview, it will make them more likely to succeed. In fact, the opposite is true – there’s such a thing as “overdoing it,” and if you’re really exhausted, your performance will drop.

Instead, make sure you have time to study and rest. I know you’ve probably heard it a million times before, but sleep is very important in these types of scenarios. Also, make sure that you make time for personal activities – again, boredom won’t do you any good!

Another tip I can give you revolves around self-study. Naturally, there are many ways you can learn. However, a good method of choice seems to be one that involves sticky notes.

What you can do is take a tutorial like this one and write the questions and answers on both sides of the note – that’s a great way to memorize information. You can also stick stickers all around, so that no matter what you do, you always see it and passively revise the course material.

Job Interview Tips: During Interview

You’ve done all the reading and studying you could, and now it’s time to show what you’ve learned. The first thing you should do is leave a lasting and good first impression. Smile, be polite and try to loosen up – your potential employer will most likely appreciate it.

Now, all you need to do during the interview is to show that you have put in the effort to study the Jenkins interview questions and that you have a reliable personality. The questions part is easy – your interviewer asks, and you answer. Try not to give a single answer to a blank statement – describe it in two or three sentences as best you can. This will show that you are really knowledgeable about the topic.

Regarding your character – be humble, don’t try to artificially impress your employer, and not appear grumpy or disrespectful. Simple like that!

Job Interview Tips: After Interview

There’s honestly not much you can do after the interview. Of course, you probably shouldn’t be calling your interviewer twenty times a day asking if you got the job – not the best idea!

Try to relax – they will reward you! One thing you can do at this point is to reflect on the experience this job interview has given you, and how you can use it in future interviews.

Conclusion

In this tutorial, we’ve talked about the basics you should know when thinking about your Jenkins job interview, covered some of the more popular Jenkins interview questions for experienced developers and covered what Jenkins is all about. I also give you some general tips that you can apply before, during and after your job interview.

As the DevOps philosophy becomes more popular and widespread, the need for qualified developers is increasing. Since DevOps is such a broad term, such a developer should have an equally broad range of capabilities – knowing how to use Jenkins is one of them. Since the concept of automation is taking the programming and development world by storm, tools like Jenkins and Selenium become essential if you want to keep up with the market. This, in turn, creates great job opportunities.

Study hard, remember to take a break and be yourself – you’ll get that job interview!

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