Top DevOps Interview Questions and Answers (2024)

What is DevOps?

DevOps stands for Development and Operations. It is a software engineering practice that focuses on bringing development and operations teams together to automate projects at every stage. This approach makes it easy to automate project service management to help achieve operational-level goals and improve understanding of the technology stack used in production.

This practice is related to agile methodologies and focuses primarily on team communication, resource management, and teamwork. The main benefits of following this structure are the speed of development and resolution of issues at the production level, the stability of the application, and the innovation involved behind it.

DevOps tools

DevOps is an approach that aims to improve the productivity and quality of product development. The main tools used in this method are:

• Version control system tools. For example: git.
• Continuous integration tools. For example: Jenkins
• Continuous testing tools. For example: Selenium
• Configuration management and deployment tools. For example: Puppet, Chef, Ansible
• Continuous monitoring tools. For example: Nagios
• Containerization tools. For example: Docker

Organizations that adopt this approach have reportedly completed nearly thousands of deployments in a single day, resulting in improved reliability, stability, and security, as well as increased customer satisfaction. Finish your next technical interview with confidence! Take a free mock interview to get instant feedback and referrals ⚡️ 💡 to a free mock interview

What are the common DevOps interview questions for new students

Who is a DevOps Engineer?

DevOps Interview Questions Analysis: A DevOps engineer is someone who works with both software developers and IT staff to ensure smooth code releases. They are typically developers who have developed an interest in the areas of deployment and operations or system administrators who have developed a passion for coding to move to the development side.

In a nutshell, a DevOps engineer is someone who understands the SDLC (Software Development Life Cycle) and the automation tools used to develop CI/CD pipelines.

Collection of DevOps Common Interview Questions and Answers: Why Did DevOps Become Famous?

These days, the market window for products has drastically decreased. We see new products almost every day. This provides consumers with a myriad of options, but at the cost of a highly competitive market. Organizations can’t afford to release big features after a gap. They tend to release small features to their customers on a regular basis so that their products don’t get lost in the sea of competition.

Customer satisfaction is now the motto of the organization and has become the goal of any product’s success. To achieve this, companies need to do the following:

• Frequent feature deployments
• Reduce the time between bug fixes
• Reduce the release failure rate
• Faster recovery time in the event of a failed release.
• To achieve all of the above, and thus achieve seamless product delivery, the DevOps culture acts as a very useful tool. Because of these advantages, multinational companies such as Amazon and Google have adopted this approach, resulting in improved performance.

What is SSH used for?

SSH stands for Secure Shell and is a management protocol that allows users to access and control remote servers over the Internet to work using the command line.

SSH is a previously known secure encrypted version of Telnet, which is unencrypted and insecure. This ensures that communication with the remote server takes place in encrypted form.

SSH also has mechanisms for remote user authentication, input communication between the client and host, and sending output back to the client.

What is configuration management?

Configuration management (CM) is basically the practice of systematically handling changes so that a system doesn’t lose its integrity for a period of time. This involves certain policies, techniques, procedures, and tools for evaluating change proposals, managing them, tracking their progress, and maintaining proper documentation for them.

CM helps provide management and technical guidance for the design and development of appreciation.

The following diagram provides a brief overview of what CM is all about:

What is the importance of configuration management in DevOps?

Configuration management (CM) helps teams automate time-consuming and tedious tasks, improving an organization’s performance and agility.

It also helps to achieve consistency and improve the product development process by employing design streamlining, extensive documentation, controls, and change implementation during all phases/releases of the project.

What does CAMS stand for in DevOps?

CAMS stands for Culture, Automation, Measurement, and Sharing. It represents the core behavior of DevOps.

What is Continuous Integration (CI)?

Continuous integration (CI) is a software development practice that ensures that developers integrate their code into a shared repository after they have finished working on the feature. Each integration is validated through an automated build process that allows teams to detect issues in their code at a very early stage, rather than discovering them after deployment.

Based on the above process, we can have a brief overview of the CI process.

• Developers regularly check out code to their local workspace and work on the features assigned to them.
• Once they’re done, the code is committed and pushed to a remote shared repository that is processed by using an effective version control tool like git.
• The CI server keeps track of changes made to the shared repository and extracts changes as soon as they are detected.
• The CI server then triggers the build of the code and runs the unit and integration test cases (if setup).
• The team is informed of the build results. If the build fails, the team must resolve the issue early and then repeat the process.

Why do you need continuous integration?

By using continuous integration for development and testing, we have seen an improvement in software quality and a significant reduction in the time it takes to deliver software functionality.

This also allows the development team to detect and fix bugs in the initial phase, as every commit to the shared repository is built automatically and run against unit and integration test cases.

What is a Continuous Test (CT)?

What are the Common DevOps Interview Questions? Continuous testing (CT) is that phase of DevOps that involves the process of running automated test cases as part of an automated software delivery pipeline with the sole purpose of getting immediate feedback on the quality and validation of the business risks associated with building automated code developed by developers.

Using this phase will help the team test each build continuously (once the developed code has been pushed), giving the development team a chance to get immediate feedback on their work and ensuring that these issues don’t end up in an SDLC loop at a later stage.

Doing so will greatly speed up the workflow that developers follow to develop their projects due to the lack of manual intervention steps to rebuild the project and run automated test cases every time a change is made.

What are the three important DevOps KPIs?

Several KPIs for DevOps are as follows:

• Reduce the mean time it takes to recover from failures.
• Increase the frequency of deployments where deployments occur.
• Reduce the percentage of failed deployments.

Intermediate Interview Questions

Explain the different phases of a DevOps approach.

DevOps Interview Questions Analysis: There are mainly 6 stages of DevOps, and they are:

Planning:

This is the first phase of the DevOps lifecycle and involves a thorough understanding of the project to ultimately develop the best product. When done correctly, this phase provides a variety of inputs needed for the development and operations phases. This phase also helps the organization to clarify the project development and management process.

Tools such as Google Apps, Asana, Microsoft Teams, etc. are used for this purpose.

Develop:

The planning phase is followed by the development phase, which builds the project by developing the system infrastructure, developing features by writing code, and then defining test cases and automating processes. Developers store their code in a code manager called a remote repository, which allows for viewing, modifying, and versioning code, which helps teams collaborate.

Use tools like git, IDEs like eclipse, IntelliJ, and tech stacks like Node, Java, and more.

Continuous Integration (CI):

This phase allows for automation of code validation, builds, and tests. This ensures that changes are made correctly without development environment errors, and also allows errors to be identified at the initial stage.

Tools like Jenkins, circleCI, etc. are used here.

Deploy:

DevOps uses tools and scripts to help deploy automation processes, with the ultimate goal of automating the process through feature activation. Here, cloud services can serve as a force to help upgrade from limited infrastructure management to cost-optimized management with unlimited resource potential.

Use tools like Microsoft Azure, Amazon Web Services, Heroku, and more.

Operate:

Due to the dynamic changes in infrastructure, this phase typically occurs throughout the lifecycle of the product/software. This provides the team with an opportunity to improve product availability, scalability, and effective conversion.

Commonly used tools at this stage are Loggly, BlueJeans, Appdynamics, etc.

Monitor:

Monitoring is a permanent phase of the DevOps approach. This phase is used to monitor and analyze information to understand the state of the software application.

Common tools like Nagios, Splunk, etc.
 

How is DevOps different from agile methods?

DevOps is a practice or culture that allows development and operations teams to collaborate to achieve successful product development. This involves leveraging practices such as continuous development, integration, testing, deployment, and monitoring of the SDLC cycle.

DevOps attempts to bridge the gap between developers and operations teams to release products effectively.

Agile is nothing more than a software development methodology that engages customers through feedback and focuses on incremental, iterating, and rapid release of software features. This approach bridges the gap between the understanding of the needs of the customer and the developer.

What is the difference between continuous deployment and continuous delivery?

The main differences between continuous deployment and continuous delivery are given below:

Continuous deployment	Continuous delivery
Deployment to production is fully automated and requires no human/human intervention.	During this process, a certain amount of manual intervention with the approval of the manager is required before deployment to the production environment.
Here, the application runs according to an automated set of instructions and does not require approval.	Here, the work of the application depends on the decision of the team.

What Are Your Thoughts On The Anti-Pattern Of DevOps?

Patterns are the most commonly followed by a large number of entities. If a pattern is adopted by an organization only because others are following it without measuring the organization’s requirements, then it becomes an anti-pattern. Similarly, there are multiple myths surrounding DevOps that can lead to anti-patterns, which are:

• DevOps is a process, not a culture.
• DevOps is all about Agile.
• There should be a separate DevOps group.
• DevOps solves all the problems.
• DevOps is the equivalent of a developer running a production environment.
• DevOps follows development-driven management
• DevOps is less focused on development.
• Since we’re a unique organization, we don’t follow the crowd, so we don’t implement DevOps.
• We don’t have the right people, so we can’t implement a DevOps culture.

Can you tell me something about Memcached?

Memcached is an open-source, free, in-memory object caching system that is high-performance, distributed, and versatile. It is primarily used to speed up dynamic web applications by reducing database load.

Memcached can be used in the following scenarios:

• Cache profiles in social network domains such as Facebook.
• Web page caching in a content aggregation domain.
• Profile tracking in ad targeting domains.
• Session caching in e-commerce, gaming, and entertainment.
• Database query optimization and scaling in location-based service areas.

Benefits of Memcached:

• Use Memcached to speed up application processes by reducing hits to databases and reducing I/O access.
• It helps determine which steps to follow more frequently and helps decide what to cache.

Some of the disadvantages of using Memcached are:

• In the event of a failure, data is lost because it is neither a persistent data store nor a database.
• It is not an application-specific cache.
• Large objects cannot be cached.

What are the various branching strategies used in a version control system?

What are the Common DevOps Interview Questions? Branching is a very important concept in version control systems like Git that helps teams collaborate. Some of the most commonly used branch types are:

Feature branches

• This branch type ensures that the specific functionality of the project is maintained in the branch.
• Once the functionality is fully validated, the branch is merged into the main branch.

Task branching

• Here, each task is maintained in its own branch, and the task key is the branch name.
• Naming the branch name to the task name makes it easy to identify which task is overlaid in which branch.

Publish branches

• This type of branch is completed once a set of features for release is completed, and they can be cloned into a branch called a release branch. No other features will be added to this branch.
• Only bug fixes, documentation, and release-related activities are done in the release branch.
• Once everything is ready, the release is merged into the main branch and marked with the release version number.
• These changes also need to be pushed to the development branch, which evolves as new features are developed.

The branching strategies followed vary from company to company, depending on their requirements and policies.

Can You List Some KPIs That Measure The Success Of DevOps?

KPIs stand for Key Performance Indicators. Some popular KPIs used to measure the success of DevOps are:

• Application usage, performance, and traffic
• The percentage of automated test cases passed.
• Application availability
• Change the volume request
• Customer tickets
• Frequency and timing of successful deployments
• Error/failure rate
• Failed deployments
• Time to Detect (MTTD)
• Recovery Time (MTTR)

Collection of DevOps Common Interview Questions and Answers: What is CBD in DevOps?

CBD stands for component-based development. It’s a unique way to do product development. Here, developers are constantly looking for existing well-defined, tested, and validated code components, reducing the burden of developers developing from scratch.

What is a resilience test?

Resiliency testing is a software process that tests the behavior of an application in an uncontrolled and chaotic situation. It also ensures that there is no loss of data and functionality after experiencing a malfunction.

Can You Tell The Between Continuous Testing And Automated Testing?

DevOps Interview Question Analysis: The differences between continuous testing and automated testing are as follows:

Continuous testing	Automated testing
This is the process of executing all automated test cases and completing them as part of the delivery process.	It’s a process that replaces manual testing by helping developers create test cases that can be run multiple times without human intervention.
This process focuses on the business risks associated with releasing software early.	This process helps developers understand if the features they are developing are error-free through a set of pass/fail points as a reference.

Can You Talk About DevOps Pipelines?

In general, a pipeline is a set of automated tasks/processes that are defined and followed by a software engineering team. A DevOps pipeline is a type of pipeline that allows DevOps engineers and software developers to compile, build, and deploy software code to production efficiently and reliably in an easy manner.

The following diagram shows an example of an effective DevOps pipeline for deployment.

The process is as follows:

• The developers are committed to completing a feature.
• The developer deploys his code to a test environment.
• Testers are working to verify the feature. Business teams can also intervene and provide feedback.
• Developers work on testing and business feedback in a continuous and collaborative manner.
• The code is then released to production and validated again.

Tell Me A Bit About What Ansible Works In DevOps

It is a DevOps open-source automation tool that helps modernize the application development and deployment process in a faster manner. It has gained popularity due to its simplicity of understanding, using, and adopting, which has largely helped people across the globe to work in a collaborative way.

Ansible	Developers	operate	quality assurance	Business/Customer
Challenge	Developers tend to focus a lot of time on tools rather than delivering results.	Operations teams need unified technology that can be easily used by different skill sets.	The quality assurance team needs to keep track of what has changed in the feature and when.	Customers are concerned about getting products to market as quickly as possible.
Need	Developers need to respond to new features/bugs and scale the workload based on demand.	Operations teams need a central management tool to monitor disparate systems and their workloads.	Quality assurance teams need to focus on minimizing the risk of human error in defect-free products.	Customers need to create a competitive advantage in the market for their products.
How can Ansible help?	Help developers catch bugs early and help them execute faster deployments in a reliable manner.	Help operations teams reduce tracking IT staff and reduce the time it takes to deploy. In addition, Ansible helps them perform automated patching.	Help QA teams build automated test cases that are not affected by the environment for more reliable and accurate results. Help define the same security baselines and help them reduce the burden of following traditional documentation.	Help business teams ensure IT teams are on the right track. It also helps them optimize the time it takes for their projects to innovate and strategize. Help teams collaborate in an effective way.

How does Ansible work?

Ansible has two types of servers, categorized as:

• Control the machine
• Node

To do this, Ansible is installed on the control machine, by using an SSH management node. The location of the node will be specified and configured in the inventory of the control machine.

Ansible does not require any installation on the remote node server because it is agentless. As a result, there is no need to execute background processes while managing any remote nodes.

Ansible can manage a large number of nodes from a single control system, and I use Ansible Playbooks via an SSH connection. Playbooks are in YAML format and are capable of multitasking.

How does AWS contribute to DevOps?

AWS stands for Amazon Web Services, and it is a well-known cloud provider. AWS helps DevOps by providing:

• Flexible Resources: AWS provides flexible, readily available resources for use.
• Scalability: Thousands of machines can be deployed on AWS by taking advantage of unlimited storage and compute power.
• Automation: Many tasks can be automated using the various services provided by AWS.
• Security: AWS is secure, using a variety of security options available under Identity and Access Management (IAM) to secure application deployments and builds.

What is the readiness method for developing a project using a DevOps methodology?

The project can be developed by using DevOps in the following phases:

• Phase 1: Plan: Plan and propose an implementation roadmap through a thorough assessment of existing processes to identify areas of improvement and blind spots.
• Phase 2: PoC: Present a proof of concept (PoC) just to understand the complexities involved. Once the PoC is approved, the actual implementation of the project will begin.
• Phase 3: Follow DevOps: Once the project is ready for implementation, you can follow the actual DevOps culture by leveraging its phases such as version control, continuous integration, continuous testing, continuous deployment, continuous delivery, and continuous monitoring.

A collection of common interview questions and answers for advanced DevOps

Can You Explain The Concept Of “Shifting Left Reduces Failures” In DevOps?

In order to understand what this means, we first need to know how the traditional SDLC loop works. In a traditional cycle, there are two main aspects –

• The left side of the cycle consists of the planning, design, and development phases
• The right side of the cycle includes the stress test, the production phase, and user acceptance.

In DevOps, shifting left simply means transferring as many tasks that typically occur at the end of the application development process as possible to the early stages of application development. As we can see from the diagram below, if the shift-left operation is followed, the chances of encountering errors later in the application development are greatly reduced, as it is already identified and resolved in the early stages itself.

The most popular ways to accomplish shift-left in DevOps are:

• Work side-by-side with the development team while creating deployments and test case automations. This is the first and obvious step towards a shift left. This is done because of the well-known fact that failures that are notified in production do not often appear earlier. These failures can be directly related to:
  • The different deployers used by the development team when developing features.
  • The production deployment process is sometimes different from the development process. There may be differences in the tools, and sometimes the process can also be manual.
• Both the development and operations teams want to develop and maintain standard deployment procedures by leveraging cloud and schema capabilities. This helps give people confidence that the production deployment will be successful.
• Use the pattern feature to avoid inconsistent configuration levels in the different environments you use. This will require the development and operations teams to work together to develop a standard process that guides developers to test their applications in the development environment as they would in production.

Do you know about post-mortem wrap-up meetings in DevOps?

An after-the-fact meeting is a meeting that is scheduled to discuss whether certain issues have arisen while implementing a DevOps approach. As you conduct this meeting, it is expected that the team must identify the steps that need to be taken to avoid future failures.

What is the concept behind sudo in the Linux operating system?

Sudo stands for “superuser do”, where superuser is the root user of Linux. It is a program for Linux/Unix-based systems that allows users with the Superuser role to use certain system commands at their root level.

Can you explain the architecture of Jenkins?

Jenkins follows a master-slave architecture. As long as a commitment is made to the code, master pulls the latest code from the GitHub repository. The master request slave performs operations such as build, test, and run and generates a test case report. This workload is distributed to all slaves in a uniform manner.

Jenkins also uses multiple slaves because once the code is committed, different test case suites may need to be run for different environments.

Can you explain the concept of “Infrastructure as Code” (IaC)?

DevOps Interview Questions Analysis: As the name suggests, IaC mainly relies on the same perceived infrastructure as any code, which is why it is often referred to as “programmable infrastructure”. It simply provides a way to define and manage the IT infrastructure through the use of profiles.

This concept has become prominent due to the limitations associated with the traditional way of managing infrastructure. Traditionally, infrastructure has been managed manually, with dedicated personnel having to physically set up servers. Only after this step is completed will the application be deployed. Manual configurations and settings are often prone to human error and inconsistencies.

This also involves hiring and managing multiple people, from network engineers to hardware technicians, to manage the increased cost of infrastructure tasks. The main problem with the traditional approach is that it reduces scalability and application availability, which affects the speed of request processing. Manual configuration is also time-consuming, and administrators work desperately to ensure that the system is available for large loads if there is a sudden spike in user usage of the application. This affects the usability of the application.

IaC solves all of the above problems. IaC can be achieved in two ways:

• Imperative approach: This method “gives commands” and defines a series of instructions that can help the system reach the final output.
• Declarative approach: This approach starts by “declaring” the desired outcome, and builds the infrastructure on top of that outcome to reach the end result.

What are some common DevOps interview questions? What is “Pair Programming”?

Pair programming is an engineering practice in which two programmers work on the same system, the same design, and the same code. They follow the rules of “Extreme Programming”. Here, one programmer is called a “driver”, while the other acts as an “observer”, constantly monitoring the progress of the project for any further issues.

What is the blue/green deployment model?

The blue-green pattern is a continuous deployment, application release model that focuses on gradually shifting user traffic from a previously working version of a software or service to a new version that is nearly identical – both running in production.

The blue environment represents the old version of the application, while the green environment represents the new version.

Production traffic will gradually shift from the blue environment to the green environment, and once fully transferred, the blue environment will remain paused in case a rollback is needed.

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In this pattern, the team must ensure that two production environments are identical, but only one is LIVE at a given point in time. Since blue environments are more stable, LIVE is usually a blue environment.

What is the Dog Stake Effect? How can it be prevented?

It is also known as cache stampede, which occurs when a large parallel computing system with a caching strategy is subjected to a very high load. It is known as an event that occurs when a cache expires (or invalidates) and multiple requests hit a website at the same time. The most common way to prevent dogpiling is to implement semaphore locks in the cache. When the cache in the system expires, the first process to acquire the lock generates a new value to the cache.

What steps do I need to take to configure a git repository to run code integrity checks before any commits? If the sanity test fails, how do you prevent it from happening again?

A soundness test, also known as a smoke test, is a process used to determine whether it is reasonable to conduct a test.
Git repositories provide a hook called pre-commit, which is triggered before the commit happens. This hook can be used to write a simple script to implement smoke testing.

The script can be used to run other tools, such as linter, and perform sanity checks on changes that will be committed to the repository.

The following code snippet is an example of such a script:

#!/bin/sh
files=$(git diff –cached –name-only –diff-filter=ACM | grep ‘.py$’)
if [ -z files ]; then
exit 0
fi
unfmtd=$(pyfmt -l $files)
if [ -z unfmtd ]; then
exit 0
fi
echo “Some .py files are not properly fmt’d”
exit 1

The above script checks that any .py files to be submitted are properly formatted by using the python formatting tool pyfmt. If the file format is incorrect, the script prevents the changes from being committed to the repository by exiting status 1.
 

How do I make sure that the script is run every time I get a new commit through the git push repository?

Depending on when the script must be triggered exactly, there are three ways to set up a script on the target repository for execution. These means are called hooks, and they are of three types:

• Pre-receive hook: This hook is called before the reference is updated when the commit is pushed. This hook can be used to ensure that scripts related to the execution of the development strategy are run.
• Update hook: This hook triggers the script to run before any updates are actually made. This hook is called once for each commit that has been pushed to the repository.
• Post-receive hook: This hook helps trigger the script after the target repository accepts the update or change. This hook is great for configuring deployment scripts, any continuous integration-based scripts, or sending email notification processes to your team, among other things.

DevOps Common Interview Questions and Answers Collection Conclusion

DevOps is a culture shift practice that has helped and continues to help many businesses and organizations in tremendous ways. It helps bridge the conflict between the goals and priorities of the developer (who constantly need change) and the operations team (who constantly resists change) by creating a smooth path for continuous development and continuous integration. Due to the increasing demand for DevOps practices, there are huge benefits to becoming a DevOps engineer.