DevOps Interview Questions (Top 30)

If you are looking for DevOps Interview Questions look no further. We have compiled a list of the most frequently asked DevOps Interview Questions. Until recently, development engineers frequently worked in isolation, restricting their wisdom and skill sets to testing and coding, while Ops engineers might concentrate on infrastructure and delivery configuration tasks, with minimal understanding of software development.

But, with all the rapid increase of the IT realm and engineering progress, the conventional strategy of IT companies has witnessed a paradigm change. A poll conducted by Indeed.com proves that the average yearly salary of a DevOps engineer from the U.S. is roughly $123,439.

If you have begun cross-training to prepare development and operations functions in the IT sector, you know that it’s a tough field that will take some true groundwork to split. Below are a few of the most Frequent DevOps Interview Questions and Answers which may assist you as you prepare yourself for DevOps functions in the business.

DevOps Interview Questions (The top 30)

Q1. What are the fundamental differences between DevOps & Agile?

Here are the differences between the two are listed down in the table below. 

Q2. What is the need for DevOps?

In my opinion, this response should begin by explaining the overall market trend.  Rather than releasing big collections of features, businesses are attempting to determine if small features can be transported to their clients through a set of release trains.  This has many benefits like quick feedback from clients, a better quality of applications, etc. which then contributes to high customer satisfaction. 

1.     Increase deployment frequency

2.         The lower failure rate of new releases

3.     Shortened lead time between repairs

4.     Faster mean time to recovery in the event of new release crashing

DevOps fulfills these requirements and assists in achieving seamless software shipping.  It is possible to give examples of businesses like Etsy, Google, and Amazon that have embraced DevOps to reach levels of performance that were unthinkable even five decades back.  They do tens, hundreds, or even thousands of code deployments daily when providing world-class stability, reliability, and safety.

If I must check your knowledge of DevOps, you ought to be aware of the difference between Agile and DevOps.  This second question is directed towards that.

Q3. How is DevOps different from Agile / SDLC?

I’d advise you to Proceed with the below explanation:

Principles and values about how to make i.e. develop applications. For example: if you have any ideas and you would like to turn these ideas into working applications, you may use the Agile principles and values as a means to do that. However, applications may only be working on a developer’s laptop or in a test atmosphere. You need a way to quickly, easily, and repeatably transfer that software into manufacturing infrastructure, in a secure and easy way.

Expression Agile software development methodology focuses on the creation of applications but DevOps, on the other hand, is responsible for development in addition to the installation of the applications in the safest and most dependable way possible. Here is a blog that will provide you with more info on the development of DevOps.

Now remember, you’ve got Included DevOps tools in your previous response to be ready to answer some questions related to this

Q4. Which are the top DevOps tools? Which tools have you worked on?

Here are the most popular DevOps tools mentioned below:

• Git: Version Control System tool
• Jenkins: Continuous Integration tool
• Selenium: Continuous Testing tool
• Puppet, Chef, Ansible: Configuration Management and Deployment tools
• Nagios: Continuous Monitoring tool
• Docker: Containerization tool

Want, but be sure that you include the aforementioned tools in your response.

The next part of the response has two possibilities:

1. If you have experience with all the aforementioned tools then you can state I have worked on these tools for creating good excellent software and deploying this software easily, often, and reliably.
2. For those who have experience only with a few of the above-mentioned tools then mention these tools and say that I’ve a specialty in these tools and have an overview of the remaining tools.

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Q5. How does DevOps Tools work together?

Here is a generic logical flow where everything gets automated for seamless delivery. However, this flow may vary from organization to organization as per the requirement.

1. The Developers build the code and this initial code is managed by Version Control System tools like Git etc.
2. Developers push this code to the Git repository and any amends made in the code is done to this Repository.
3. Jenkins pulls code from the repository using the Git plugin and develops it using tools like Ant or Maven.
4. Configuration management tool-set like puppet deploys and provisions the testing environment and then Jenkins pushes this code to the test environment on which testing is done using tools like selenium.
5. Once the code is tested, Jenkins pushes it for deployment on the production server which is managed by Puppet.
6. After release and deployment, It is continuously reviewed by tools like Nagios.
7. Docker containers offer a testing environment to test the released features.

Q.6 What are the Benefits of DevOps?

With this answer, you may use your previous experience and explain how DevOps assisted you in your past job. If you do not have any experience, then you may mention the below benefits.

Technical benefits:

• Constant software delivery
• Less Complicated problems to Repair
• Quicker resolution of issues
• Business benefits:

Quicker delivery of attributes

• More stable working environments
• More time available to add value (instead of fix/maintain)

Q.7 DevOps Interview Questions: What’s Version control?

This may be the easiest question you may face in the interview. My suggestion is to first give a definition of Model control. It’s a system that records changes to a file or set of files over time so you can recall certain versions later. Version control systems include a central shared repository where teammates can commit changes to a file or set of documents. Then you may mention the applications of version control.

Version control lets you:

• Revert files back to a previous condition.
• Revert the whole project back to a previous state.
• Watch who last altered something which may be causing an issue.
• Know Who introduced a problem and when.

Q.8 Describe branching strategies you have used.

To examine your branching experience so inform them about how you’ve used branching on your past job and what purpose does it functions for, you can refer to the below tips:

• Feature branching

A characteristic branch model keeps all the changes for a specific feature inside a branch. After the feature is fully tested and supported by automatic tests, the division is then merged into master.

• Task branching

In this model, each task is implemented on its own branch with the job key included in the division name. It’s not hard to determine which code implements which job, just search for the task key from the branch name.

• Release branching

When the develop branch has got enough features to get a release, it is possible to clone that division to form a Release branch. Creating this branch starts another release cycle, so no new features can be added after this stage, just bug fixes, documentation creation, and other release-oriented tasks should go in this division. Once it’s ready to ship, the launch becomes merged into master and tagged with a version number. Additionally, it ought to be merged back into the develop branch, which could have improved since the launch was initiated.

At the end tell them Basic branching operations like delete, merge, checking out a branch.

I will suggest that you try this question by first explaining the architecture of git as shown in the below diagram. You can refer to the explanation given below:

Q.9 What is Git?

Git is a Distributed Version Control system (DVCS). It can track changes to a file and lets you revert back to any specific change.

Its distributed architecture provides many benefits over other Version Control Systems (VCS) like SVN one significant advantage is that it does not rely on a central server to keep all the versions of a project’s files. Instead, every programmer “clones” a copy of a repository I have shown in the diagram below with “Local repository” and has the full history of the project on his hard drive so that when there is a server outage, all you need for retrieval is one of your teammate’s neighborhood Git repository.

There is a fundamental cloud repository as well where developers can commit changes and share it with other teammates as you can see from the diagram where all collaborators are committing changes “Remote repository”.

Q.10 In Git how can you revert a commit that is already pushed and made public?

There can be two answers to this question to make sure that you include both because some of the below choices can be used depending on the situation:

Remove or repair the bad file in a new commit and push it to the remote repository. This is the most natural way to repair an error. Once you have made necessary changes to the document, dedicate it to the remote repository for that I’ll use

git commit -m “commit message”

Create a new commit that undoes all changes that were made in the bad commit.to do so I’ll use a command

git revert <name of bad commit>

Q.11 How will you know in Git if a branch has been merged into master?

I will suggest you add the below-mentioned commands:

Git branch — merged lists the branches which have been merged into the current branch.

Git branch — no-merged lists the branches which haven’t been merged.

Q.12 What is meant by Continuous Integration?

I will recommend that you start this response by giving a little definition of Continuous Integration (CI). It’s a development practice that needs developers to incorporate code into a shared repository a few times each day. Each check-in is then confirmed through an automatic build, allowing teams to detect problems early.

Q.13 What are the success factors for Continuous Integration?

Here you need to mention the requirements for Continuous Integration. You could include the following points in your response:

• Maintain a code repository
• Automate the build
• Create the construct self-testing
• Everyone commits to the baseline daily
• Every commit (to baseline) should be built
• Maintain the construct quickly
• Evaluation in a replica of the production environment
• Make it easy to get the latest deliverables
• Everyone can see the results of this latest build
• Automate deployment

Q.14 Mention some of the plugins in Jenkins.

Below, I’ve mentioned some Essential Plugins:

• Maven 2 project
• Amazon EC2
• HTML Publisher
• Copy artifact
• Join
• Green Balls

Q.15 What’s Automation Testing?

Automation testing or Test Automation is a process of automating the manual procedure to check the application/system under evaluation. Automation testing entails the use of different testing tools that enables you to create test scripts that may be executed repeatedly and does not require any manual intervention.

Q.16 What are the Advantages of Automation Testing?

I’ve listed down some benefits of automation testing. Include these in your response and you can add your personal experience of how Continuous Testing helped your previous business:

• Supports execution of repeated test instances
• Aids in analyzing a large test matrix
• Enables parallel implementation
• Encourages unattended execution
• Improves accuracy thereby decreasing human generated mistakes
• Saves time and money

Q.17 Why are configuration management procedures and tools important?

Proceed to describe the need for storing and maintaining data, keeping an eye on growth builds, and simplified troubleshooting. Do not forget to mention the important CM tools which may be utilized to attain these objectives. Talk about how tools such as Puppet, Ansible, and Chef assist in automating software deployment and configuration on many servers.

Q.18 What’s a source in Chef?

My suggestion is to define Resources. A Resource represents a bit of infrastructure and its desired condition, like a package that ought to be set up, a service that needs to be running, or a document that needs to be generated.

Describes the desired state for a configuration item.

• Declares the actions required to bring that thing to the desired state.
• Specifies a source type like template, package, or assistance.
• Lists additional details (also referred to as resource properties), as needed.
• Are grouped into recipes, which explain working configurations.

Q19. What do you mean by the recipe in Chef?

For this response, I will advise you to use the flow: first, define Recipe. A Recipe is a group of Resources that describes a specific configuration or policy. A Recipe describes everything that’s required to configure a part of a system.

Following the definition, describe the functions of Recipes by adding these points:

• Install and configure software components.
• Deploy software.
• Execute different recipes.

Q.20 How can a Cookbook differ from a Recipe in Chef?

The solution to this is fairly direct. You can just state,”a Recipe is a group of Resources, and mostly configures a software bundle or some part of the infrastructure. A Cookbook groups collectively Recipes and other info in a manner that’s more manageable than having only Recipes alone.”

Q.21 What’s the difference between Active and Passive check in Nagios? 

For this response, first, point out the simple difference between Active and Passive checks.  If your interviewer is looking unconvinced with the above explanation then you may also mention some important characteristics of both Active and Passive checks: Passive checks are helpful for monitoring services which are:

• Asynchronous in nature and can’t be monitored effectively by polling their standing on a regularly scheduled basis. 
• Found behind a firewall and can’t be checked actively in the monitoring host. 

The primary features of Actives checks are as follows:

• Active checks are conducted on a regularly scheduled basis.  

Q.22. What’s version control and should VCS be utilized?

Proceed through the changes made over a time period and assess what works versus what does not.

• Revert particular documents or special projects back to an older version.
• Examine difficulties or errors that have occurred because of a specific change.

Using VCS gives developers the flexibility to simultaneously work on a certain file and all modifications can be combined later.

Q. 23 How Can Nagios help with Distributed Tracking?

 The interviewer will probably be expecting a response related to the distributed architecture of Nagios.  Thus, I suggest that you answer it in the undermentioned format: With Nagios, you can track your entire business by using a distributed monitoring strategy where local servant instances of Nagios perform monitoring tasks and report back the results to one master.  You handle all settings, notifications, and reporting from the master, while the slaves do all of the work.  This design takes advantage of Nagios’s capacity to use passive tests i.e. external processes or applications that deliver results back to Nagios.  In a distributed configuration, these external programs are different instances of Nagios.

Q.24 What are containers? 

My suggestion would be to clarify the need for containerization first, containers are utilized to provide a consistent computing environment from a developer’s laptop to a test environment, from a staging environment to production. Now provide a definition of containers, a container is made up of a complete runtime environment: an application, and all of its dependencies, libraries and other binaries, and configuration files needed to run it, bundled into a single package.  Containerizing the application platform and its dependencies eliminates the gaps in OS distributions and underlying infrastructure.

Q.25 What’s Docker container?

This is an important question so just be certain that you don’t deviate from the subject. I advise you to follow the below mentioned format:

Docker containers include the program and all its dependencies but discuss the kernel along with different containers, operating as isolated procedures in userspace on the server operating system. Docker containers aren’t tied to any infrastructure: they operate on any computer, on any infrastructure, and in any cloud.

Now describe how to make a Docker container, Docker containers can be produced by creating a Docker picture and then running it or you could use Docker images that are found on the Dockerhub.

Docker containers are essentially runtime instances of Docker pictures.

Q.26 What’s Docker Swarm?

You should begin this answer by describing Docker Swarm. It’s native clustering for Docker which turns a pool of Docker hosts into a single, virtual Docker host. Docker Swarm serves the normal Docker API, any instrument that currently communicates with a Docker daemon may use Swarm to scale to multiple hosts.

I’ll also suggest you add some tools that are supported:

• Dokku
• Docker Compose
• Docker Machine
• Jenkins

Q.27 Tell us how you’ve used Docker in your previous position? 

Explain how you’ve used Docker to assist in rapid deployment.  Explain how you’ve scripted Docker and utilized Docker with other tools such as Puppet, Chef, or Jenkins.  In case you’ve got no previous practical experience in Docker and have previous experience with other tools in a comparable distance, be honest and describe the same.  In cases like this, it makes sense if you’re able to compare different tools to Docker concerning functionality.

Q.28 What platforms does Docker run on?

I will start this answer by stating Docker runs on only Cloud and Linux platforms and then I will cite the below vendors of Linux:

• Ubuntu 12.04, 13.04 et al
• Fedora 19/20+
• RHEL 6.5+
• CentOS 6+
• Gentoo
• ArchLinux
• openSUSE 12.3+
• CRUX 3.0+

Cloud:

• Amazon EC2
• Google Compute Engine
• Microsoft Azure
• Rackspace

Note that Docker doesn’t run on Windows or Mac.

Q.29 What is Puppet? What is the need for it in DevOps?

Puppet is a Configuration Management and installation tool for administrative jobs.

This tool aids in automating the provisioning, configuration, and management of Infrastructure and Systems.

Say, you must bring up ‘n’ number of Servers with ‘x’ number of VMs (Virtual machines) on them. Each VM has to be configured for specific users, groups, services, applications, and databases, etc.

The whole infrastructure can be loaded up with the assistance of Puppet programs re-using the codes on multiple servers.

Key feature: Idempotency

The identical set of configurations can be run several times to construct a machine on a machine, as Puppet would allow only particular configurations to be run.

Q 30 What are the best practices for DevOps implementation?

Today organizations are seeking to deliver the software quicker and from this point of view here are my ideas on how DevOps can cause efficient communication with all the stakeholders such as the operations staff.

• Every company has certain business targets and DevOps implementation should align with this.  There should be a definite demand for change. 
• Encouraging communication and cooperation especially between operations and development. 
• Automation is the key and needs to be performed and completed where possible within the SDLC phases to facilitate the functioning of DevOps. 
• The tools used in DevOps should incorporate very well.  From the viewpoint of any industrial tools such as IBM Rational CLM or Microsoft TFS, execution of DevOps is great because it’s from one vendor.  Similarly, you need to look at open source tools that integrate to provide similar desired effects. 

• DevOps implementation isn’t effective without CI and CD practices.  So constant integration of your code with rigorous testing and performing constant delivery is the key for this. 
•  It’s essential important for the Ops staff to make certain that the applications are functioning very well at acceptable levels.  If required they’ll have to work together with the development teams to create some tools that would help to create the ideal monitoring capabilities into the software. 

Conclucsion – DevOps Interview Questions

These DevOps Interview Questions are based on real-world interviews and many times the interviewers are seen asking these types of DevOps Interview Questions. However, these are not to be taken as the only question that you might be asked as the actual DevOps Interview Questions totally depends on the organization, their requirements, and the project(s).

In this post, we have only short-listed the top 30 DevOps Interview Questions from around the world. The upper mentioned DevOps Interview Questions and answers are from senior DevOps experts who have been working in the field for years and mostly conducting interviews themselves. Hence this just might be your best source for DevOps Interview Questions.