DevOps – a renowned software development practice that many companies adopt into their workflow – has been drawing a great deal of attention lately. More and more companies have implemented this approach, including large enterprises such as Netflix, Facebook, and Amazon. As a matter of fact, DevOps-related jobs have become one of the most promising career choices for IT professionals today.

You might be among the developers who are planning to advance your career as a DevOps engineer, analyst, or specialist. Besides the required technical skills, a DevOps job interview can be tough without diligent preparation.

This blog post presents more than 30 of the most common DevOps interview questions, neatly broken out into themes, so you can ace your next interview and successfully get that dream job.

DevOps terms and definitions

1. What is DevOps?

In general, DevOps is the gray area between development (Dev) and operations (Ops) teams in a product development process. DevOps is a culture in which communication, integration, and collaboration in the product development cycle are emphasized. Thus, it eliminates the silos between software development and operations teams, allowing them to focus on rapid and continuous product deployment.

2. What is continuous integration?

Continuous integration (CI) is the process of automatically integrating code changes from multiple developers into a shared repository. Automated tests are utilized to verify and affirm the additional codes generate no conflict with the existing codebase. Ideally, code changes should be merged multiple times a day, at every commit, with the help of CI tools.

3. What is continuous delivery?

Continuous delivery (CD), together with CI makes a complete flow for deliverable code packages. In this phase, automated building tools are applied to compile artifacts (e.g., source code, test scripts, configuration files, and environments) and have them ready to be delivered to the end user. With that in mind, in a CD environment, new releases are just one click away from being published with fully functional features and minimal human intervention.

For more details, please refer to our introduction to CI/CD article.

4. What is continuous deployment?

Continuous deployment takes CD to the next level by having new changes in code integrated and delivered automatically into the release branch. More specifically, as soon as the updates pass all stages of the production pipeline, they are deployed directly to the end-user without human intervention. Thus, to successfully utilize continuous deployment, the software artifacts must go through rigorously established automated tests and tools before being deployed into the production environment.

5. What is continuous testing and its benefits?

Continuous testing is the practice of applying automated tests early, gradually, and adequately in the software delivery pipeline. In a typical CI/CD workflow, builds are released in small batches. Therefore, it is impractical to manually perform test cases for each delivery. Automated continuous testing eliminates the manual steps and turns them into automated routines, which reduces human effort. That’s why automated continuous testing is essential for the DevOps culture.

Benefits of continuous testing:

Ensures the quality and speed of builds
Enables faster software delivery and a continuous feedback mechanism
Detects errors as soon as they occur in the system
Reduces business risks and evaluates potential problems before they become real problems

6. What is version control and its uses?

Version control (or source control) is a repository in which all changes in the source code are stored and managed at all times. Version control provides an operating history of code development that allows developers to rewind if they made any mistakes, compare versions, and finalize the best version of the code. All the code versions must be updated and checked into the version control, making it the single source of truth that is applicable for all environments.

7. What is Git?

Git is a distributed version control system that tracks changes in the code repository. Utilizing GitHub flow, Git revolves around a branch-based workflow that streamlines team collaboration as their projects progress over time.

Reasons for implementing DevOps

1. Why does DevOps matter? How does DevOps benefit teams in software delivery?

In today’s digitized world, organizations must reinvent their product deployment systems to be more robust and flexible in order to keep up with the competition.

This is where the DevOps concept comes into the picture. DevOps plays a crucial part in generating mobility and agility to the entire software development pipeline, from idea to deployment and to the end-users. DevOps is the solution that drives a more streamlined and efficient process of continuously updating and improving products.

2. Explain how DevOps is helpful for developers.

In a world without DevOps, the workflow would start with developers building new codes, shipping, and integrating them, and then it’s the operation team’s duty to package and deploy the codes. After that, they have to wait for feedback. And if things go wrong, they have to go back and do it all over again to solve the bugs. In this process, there is exorbitant manual communication between different teams involved in the project.

Applying DevOps reduces developer tasks to building code only, as CI/CD practices consolidate and automate the remaining tasks. Combining the engineering and operation teams helps to create better communication and collaboration as processes become more transparent and accessible by all team members.

3. Why has DevOps gained popularity in software delivery recently?

DevOps has gained attention over the last few years primarily due to its ability to streamline the development, testing, and deployment processes for organizational operations and convert them into business value.

Technology is developing at a fast pace. Hence, organizations must adopt a new workflow – the DevOps and Agile approach – to streamline and stimulate their operations to stay ahead of the competition. DevOps’ features and benefits are reflected clearly through the successful application of the continuous deployment approach at both Facebook and Netflix, which boosted their growth without disrupting their ongoing operations.

4. What are the benefits of CI/CD?

The combination of CI and CD unifies all code changes into one single repository and runs them through automated tests, thus fully developing the product throughout all phases and making it ready for deployment at all times.

CI/CD enables organizations to roll out product updates as quickly, efficiently, and automatically as their customers expect them to be.

In short, a well-planned and well-executed CI/CD pipeline accelerates release rates and reliability and mitigates the code changes and defects of your product, resulting in much higher customer satisfaction.

5. What are some benefits of continuous delivery?

Manually releasing changes in code gives teams complete control of the product. In some cases, a new product release aligns with a bigger picture in the organization, for example, a promotion strategy with clear business purposes.

By automating repetitive and mundane tasks, IT professionals have more time to focus on improving the product without worrying about the integration progress.

6. What are some benefits of continuous deployment?

With continuous deployment, developers can focus solely on the product because their final task in the pipeline is to review pull requests and merge them to the master branch. This method enables frictionless deployment and shortens the deployment duration by releasing new features and fixes right after they have passed the automated tests.

Customers are the ones to evaluate the quality of each release. Bug fixes for new releases are easier to handle because each release is delivered in small batches.

How to effectively implement DevOps

1. Define a typical DevOps workflow.

A typical DevOps workflow can be organized into four stages:

Version control – This is the stage in which the source code is stored and managed. The version control contains different versions of the code.
Continuous integration – In this step, developers start to build components and have them compiled, validated, and tested with code review, unit testing, and integration testing.
Continuous delivery – This is the next level of continuous integration, in which the release and testing processes are fully automated. CD ensures new releases are delivered quickly and sustainably to the end users.
Continuous deployment – After the application has successfully passed all testing requirements, it is automatically deployed on the production server for release without any human intervention.

To learn more, read From DevOops to DevOps | Best Strategies to Implement for Your Team.

2. What are the core operations of DevOps?

The core operations of DevOps in terms of development and infrastructure are:

Software development
Code building
Code coverage
Unit testing
Packaging
Deployment
Infrastructure
Provisioning
Configuration
Orchestration
Deployment

3. What are some precautions that teams need to consider before implementing DevOps?

There are a few misconceptions about DevOps practices that could potentially lead to tragic failures when organizations try to apply this new approach:

DevOps is more than simply applying new tools and/or forming a new “department” and expecting it to work. In fact, DevOps is considered a culture in which development and operations teams work side by side following a mutual framework.
Organizations do not need to define a clear vision for their DevOps practices. Applying DevOps initiatives is a notable change to both development and operation teams. Therefore, having a clear roadmap, goals, and expectations for integrating DevOps in your organization will eliminate confusion and provide clear guidelines from the start.
After the DevOps practices have been applied across the organization, the management team needs to establish and nurture a continuous learning and improvement culture. Failures and problems in the system should be treated as a valuable medium for teams to learn from mistakes and prevent those mistakes from recurring.

4. What role does the SCM team play in DevOps?

Software configuration management (SCM) is the practice of tracking and keeping records of the development environment, including all the changes and adjustments made in the operating system.

In DevOps, SCM is built as codes under the umbrella of Infrastructure as Code practice.

SCM simplifies tasks for developers as they no longer have to manually manage the configuration processes. This process is now constructed in a machine-readable form and is automatically duplicated and standardized.

5. What role does the Quality Assurance (QA) team play in DevOps?

As DevOps practices become a more desired culture in innovative organizations, QA teams’ responsibilities and relevance have shown signs of decline in today’s automated world.

However, this can be considered a myth. The rise of DevOps is not equal to the end of QA roles. It only means that their working environment and required expertise are changing. Therefore, their main focus should be to professionally evolve in order to keep up with this maturing trend.

In DevOps, QA teams play a strategic role to ensure the stability of continuous delivery practices as well as perform the exploratory testing tasks that automated and repetitive tests cannot fulfill. Their insights in assessing the test and detecting the most valuable tests still play a crucial role in mitigating bugs in the last steps of a release.

6. What are some tools used for DevOps? Describe your experience working with any of these tools.

Throughout a typical DevOps lifecycle, there are various tools to support different phases of product development. The most common tools for DevOps can be divided into six key phases:

Continuous development: Git, SVN, Mercurial, CVS, Jira
Continuous integration: Jenkins, Bamboo, Hudson
Continuous delivery: Nexus, Archiva, Tomcat
Continuous deployment: Puppet, Chef, Docker
Continuous monitoring: Splunk, ELK Stack, Nagios
Continuous testing: Selenium, Katalon Platform

How to effectively implement CI/CD

1. What are some core components of CI/CD?

A stable CI/CD pipeline requires a repository management tool that acts as a version control system so that developers can keep track of changes in the software build.

In the version control system, developers can also collaborate on a project, compare between versions, and undo any mistakes they make, thus mitigating disruption to all team members.

Continuous testing and automated testing are the two most pivotal keys to successfully establishing a seamless CI/CD pipeline. Automated testing must be integrated into all product development phases (including unit, integration, and system testing) to cover all functionalities such as performance, usability, performance, load, stress, and security.

2. What are some common practices of CI/CD?

Here are some best practices for establishing an efficient CI/CD pipeline:

Develop a DevOps culture
Implement and utilize continuous integration
Deploy to every environment the same way
Fail and restart your pipeline
Apply version control
Include the database in the pipeline
Monitor your continuous delivery pipeline
Get your CD pipeline flowing

3. When is the best time to implement CI/CD?

The transition to DevOps requires a complete reshaping of your software development culture, including the workflow, organizational structure as well as infrastructure. Therefore, organizations must prepare themselves for a major change when implementing DevOps.

4. What are some common CI/CD servers?

Visual Studio

Visual Studio (VS) supports a fully developed DevOps system with agile planning, source code control, package management, testing and release automation, and continuous monitoring.

TeamCity

TeamCity is an intelligent CI server that offers framework support and c

ode coverage without any extra plugin install needed and no mods to build scripts.

Jenkins

A self-contained CI server, it supports collaboration between development and operation teams with a shared pipeline and error-tracking function. It can also be combined with hundreds of dashboard plugins.

GitLab

GitLab’s users can customize the platform for efficient continuous integration and deployment. GitLab helps CI/CD teams to accelerate in-code shipping, error identity, and program recovery rollout.

Bamboo

Bamboo is a continuous integration server for product release management automation. Bamboo keeps track of all deployments on all tools and communicates errors in real time.

5. Describe an efficient workflow for continuous integration.

A successful workflow when implementing continuous integration encompasses the following practices:

Implement and maintain a repository for the project’s source code
Automate the build and integration
Make the build self-testing
Commit changes daily to the baseline
Build all commits added to the baseline
Keep the builds fast
Run tests in a clone of the production environment
Make it easy to get the latest deliverables
Make build results easy to be monitored by everyone
Automate deployment

Differences between each terminology

1. What are some key differences between Agile and DevOps?

Basically, DevOps and Agile are complementary to each other. Agile focuses more on the values and principles of developing new software and managing a complex process in a more effective way. Meanwhile, DevOps is all about enhancing communication, integration, and collaboration between different teams, which comprise the developer and operation teams.

It takes both Agile and DevOps methods to form a product development life cycle that works seamlessly: Agile principles help shape and steer the development toward the right path and DevOps utilizes the tools to make sure the product is fully delivered to the customers.

2. What are some differences between continuous integration, continuous delivery, and continuous deployment?

CI is a practice in which code versions are continuously integrated into a shared repository. This practice ensures that new codes are automatedly tested and that errors are quickly detected and fixed.

Continuous delivery takes CI one step further by ensuring that after integration, the code base is ready to be released any time, with just a push of a button. Therefore, CI is considered a prerequisite for continuous delivery, the other essential part of the CI/CD pipeline.

As for continuous deployment, no manual step is required. Once the codes have passed the tests, they are automatically pushed to the production environment.

All three of these components (continuous integration, continuous delivery, and continuous deployment) are essential phases of implementing DevOps.

On one hand, continuous delivery is more suitable for applications that already exist with active users so that things can flow a bit slower and be more tuned. On the other hand, if you plan to release brand new software and want the whole process to be fully automated, continuous deployment is a more suitable choice for your product.

3. What are some fundamental differences between continuous delivery and continuous deployment?

Under continuous delivery, the codes in the main branch are always ready to be deployed manually. This practice allows the development team to decide when to release new changes or features to best benefit the organization.

Meanwhile, continuous deployment will have all updates and fixes in the code automatically deployed to the production environment immediately after the testing phase and without any human intervention.

4. What are the differences between continuous integration and continuous delivery?

Continuous integration helps ensure that software components work closely together. Integration should be done frequently; preferably on an hourly or daily basis. Continuous integration helps increase the frequency of code commits and reduces the complexity of connecting code from multiple developers. Eventually, this process reduces the chances for non-compatible code and redundant efforts.

Continuous delivery is the next step in the CI/CD pipeline. As the code is integrated into the shared repository continuously, continuously testing that code is made possible. There are no gaps while waiting for code to be completed before testing can occur. This ensures as many bugs are found as possible to then continuously deliver code to production.

5. What are the differences between DevOps and continuous delivery?

DevOps is more of an organizational and cultural approach that promotes collaboration and communication between both the engineering and operation teams.

Meanwhile, continuous delivery is an essential factor that contributes to the success of implementing DevOps into the product development workflow. Continuous delivery practices help to make new releases more reliable and establish a more seamless and shorter process.

The key purpose of DevOps is to effectively combine the Dev and Ops roles, remove all silos, and deliver business goals independent of continuous delivery practices.

Alternatively, continuous delivery works best when there is already a DevOps process in place. Thus, it amplifies collaboration and streamlines the unified product development cycle of the organization.

6. What are the differences between Agile, Lean IT, and DevOps?

Agile is a methodology that focuses solely on the development of software. Agile aims to iterate development, establish continuous delivery, shorten feedback loops, and improve team collaboration throughout the software development life cycle (SDLC)

Lean IT is a methodology that aims to streamline the value stream of the product development cycle. Lean focuses on eliminating unnecessary processes that do not add value and creating a flow to optimize the value streams

DevOps focuses on both the development and deployment — the Dev and Ops of the product development process. Its goal is to effectively unite the roles between automation tools and IT professionals for a more streamlined and automated process

Ready to ace your next DevOps interview?

There are countless DevOps interview questions out there that are not fully covered in this article … just yet. However, we hope these questions and suggested answers equip you with the foundational knowledge of DevOps as well as CI/CD to get you through your next interview successfully.

We will add more content to this list in the future. So if you have any suggestions on this topic, please do not hesitate to reach out to share.

In the meantime, continue your professional development journey with us via Katalon Academy and view the latest methods for effective orchestration with test automation. In addition to all of this, to better prepare for your interviews, here are some topic-specific lists of interview questions:

CI/CD Pipeline Trends for 2024: Continuous Integration & Delivery Strategy

Low-Code Software Testing: How to Get Your Org on Board

15 Best DevOps Tools For Software | 2024 Update