23 DevOps Interview Questions (And Answers)

Are you preparing for a job interview for a DevOps role, but don’t know where to start? Whether you’re a fresh graduate searching for an entry-level role or an experienced DevOps professional looking to level up your career, we’ve compiled a list of the top DevOps interview questions that are bound to crop up. We’ll cover:

• DevOps interview questions for graduates
• Intermediate interview questions for DevOps engineers
• Advanced DevOps engineer interview questions

DevOps interview questions for graduates

1. Why has DevOps become so popular?

Here, you should be able to provide a concise answer, explaining the increasing importance of DevOps in IT, and how it aims to streamline and strengthen the relationship between development and operations teams. The key is to focus on the purpose of DevOps, which is to increase collaboration, boost product delivery efficiency and produce an overall higher quality product.

2. What are some of the most popular DevOps tools?

As a graduate, you may not have experience working with DevOps tools just yet; however, it can be helpful to have a basic knowledge of some of the most popular tools that you could see yourself using on the job. Prior to your interview, we recommend checking out the following tools: Selenium. Puppet, Git, Jenkins and Ansible – and doing some research around new up-and-coming tools, too!

3. Provide an explanation of the different DevOps phases

You may be asked to explain each stage of the DevOps lifecycle, from planning to monitoring. It could look something like this:

• Planning – the initial planning phase will outline the application that needs to be developed, and the development steps to be followed.
• Development – at this stage, developers will start writing code to meet user requirements.
• Building – all code will be shared in a repository and the application will be built using the written code.
• Testing – software testers will test the application to check functionality and identify bugs, and apply appropriate fixes or rebuild if necessary.
• Release – the build is released to the production environment.
• Deployment – the build is deployed to the end-user.
• Operations – the operations team handles server configuration.
• Monitoring – the DevOps pipeline is monitored to ensure maximum productivity, taking into account customer feedback and product performance.

4. What is SSH? And, why would you use it?

Interviewers will expect you to have knowledge of SSH and its uses. SSH stands for Secure Shell, and is a network communication protocol, which enables two computers to communicate with one another. It is used to share data securely using encryption, which can be useful for sharing user information and passwords, for instance. SSH is key in DevOps to facilitate an efficient build, which is typically automated.

5. What is configuration management? And, why is it important for DevOps?

Configuration management is the process of maintaining computer software, or hardware, in a consistent state. It plays a major role in DevOps, ensuring all changes are documented, compliant and maintain consistency at scale. You should be able to provide a top-level explanation of configuration management and its purpose.

6. What does CAMS stand for?

In DevOps, CAMS stands for Culture, Automation, Measurement and Sharing. You may be asked to expand on these pillars in more detail during your interview. For more information, LinkedIn Learning is a fantastic resource to delve a little deeper into the CAMs model.

7. What is Continuous Integration (CI)? And, why is it important in DevOps?

This is another common DevOps engineer interview question to prepare for. Continuous Integration (CI) is a key part of DevOps, where code is shared in a repository. It is here where code changes are integrated and tested automatically by multiple contributors. CI is important for finding and fixing bugs more efficiently (with minimal manual effort).

8. What is Continuous Testing (CT)? And, why is it important in DevOps?

Continuous Testing is another core principle of DevOps, that involves building, testing, and delivering improvements to the software code. This stage ensures products can be delivered to the end-user quickly, without defects. Releases are small to ensure you can manage fixes easily and can be released on a daily, weekly or monthly basis. Continuous Integration has the ability to run multiple texts within seconds, saving teams time and money.

9. What are the key objectives in DevOps?

Following on from explaining what DevOps consists of, you should be able to outline some of its main benefits. This could include (but is not limited to):

• Providing continuous software delivery.
• Breaking down complex problems into smaller, more manageable increments.
• Early detection of issues, which makes for more efficient correction and fewer defects.
• Providing a stable operating environment.
• Improving communication between teams, encouraging better collaboration and higher productivity.

10. How would you go about implementing DevOps in a project?

You should be able to explain the standard procedure for approaching a project that needs to implement DevOps. This should include an assessment of existing processes to identify areas for improvement and the creation of a proof of concept (PoC) to roll out a plan of action, which is to be monitored on a regular basis. As a graduate, you would not be expected to lead DevOps implementation, but it’s good to have a broad knowledge of how this works.

11. Provide an explanation of the Infrastructure as Code (IaC) framework

Infrastructure as Code (IaC) refers to the management of infrastructure through code and machine-readable files, as opposed to manual processes. IaC is made up of three main elements: scripting, configuration management and provisioning. Developers write the code to meet infrastructure specs, these files are sent to the master server or code repository and the platform configures these to run the processes. Since this is a vital aspect of DevOps, you will need to be familiar with how IaC works, as you are likely to be asked about this during your DevOps interview.

Intermediate DevOps interview questions

1. Can you explain the differences between DevOps and the Agile Methodology?

You should be able to explain the difference between DevOps and Agile Methodology, highlighting that DevOps is a culture in which development and operations teams collaborate on projects, whereas Agile is a development methodology that focuses on incremental product releases. DevOps involves continuous development, testing, delivery and monitoring.

It can be useful to note that there are some similarities between the two, such as continuous delivery in small increments and a constant feedback loop that brings developers closer to the end-user.

2. What are anti-patterns in DevOps?

In DevOps, anti-patterns are the common response to regular errors.  It can be expected of you to understand the two characteristics of an anti-problem:

• It is a commonly used process that is no longer effective to solve the problem.
• Other documented solutions are available to solve the problem that are more effective than the anti-problem.

3. Can you explain the difference between Continuous Deployment and Delivery?

Continuous Deployment and Continuous Delivery are another two important stages of DevOps. You will be expected to understand the difference between the two, and their importance. Here are just a few examples:

4. Explain the benefits and use cases for Memcached

Memcached is an in-memory data storage system that allows for cached items to be served almost instantly. This makes it easier for development teams to power real-time applications, with faster response times and better scalability. It is worth looking into Memcached and how it can be used to support teams, and make sure you feel confident talking about this with your interviewer.

5. Explain each branching strategy used in the version control system

A branching strategy determines when and how developers branch and merge, outlines how the team functions, make improvements and troubleshoots errors. There are various different branching strategies used in DevOps, including mainline, trunk-based development, task/feature and release branching. We recommend getting a feel for these various branching strategies, as you may find yourself using a handful of them throughout your career.

6. What KPIs can you measure against to understand DevOps success?

Every business will measure the success of its DevOps implementation using KPIs. Some of the most useful metrics for this are deployment frequency, deployment time, failed deployment time, time to recovery and volume of defect. When applying for more senior roles, you will likely be more involved in measuring the success of DevOps and will need to be well-versed in relevant DevOps KPIs.

7. What role does AWS play in DevOps?

Amazon Web Services (AWS) provides services that enable a business to practice DevOps, helping automate manual tasks, manage complex projects at scale and get products to market faster and more efficiently. Explore more about AWS and how it can benefit a business, and be prepared to discuss this in relation to your role if required.

Advanced DevOps interview questions

1. What is the ‘Shift left to reduce failure’ concept and how does it work?

Understanding how to ‘shift left’ is very important in DevOps. It refers to the way in which development teams focus on quality control and bug prevention, rather than detecting issues later on in the process. This means testing typically starts much sooner than other, more traditional, development models. The term ‘shifting left’ comes from the process of going to the left side of the DevOps lifecycle.

2. What do you expect from a post-mortem meeting in DevOps?

Similar to a post-mortem examination, a post-mortem meeting in DevOps sets out to analyse an incident that has taken place, and better understand its causes to prevent it from recurring. Some of the key things that make a good post-mortem meeting include: having the right people present, avoiding the blame game and focusing on the shared goals for better, actionable outcomes.

In more advanced DevOps roles, you may be required to host post-mortem meetings and implement new initiatives according to your learnings. If you already have experience in running post-mortems, it is a good idea to talk about this and how you learnt from incidents and the actions you took to rectify issues.

3. What is Pair Programming? And how does it benefit teams?

Pair Programming is an Agile software development technique where two developers work on one computer to design, code and test. One person is called the driver who is responsible for programming, and the other is the navigator who focuses on the direction of the programme. This technique requires a high level of communication, but can be highly effective for creating code with fewer mistakes and encouraging knowledge sharing and naturally collaborative teams.

4. What is the Blue-Green Deployment Pattern? And, what are its benefits?

Blue-Green deployment is a practice that addresses the issue of transitioning from testing to production, using two parallel production environments. This means that there will be a live environment (green) for users, as well as a staging environment (blue) to run final tests before syncing the two. Some benefits of the Blue-Green deployment model include rapid release, easy rollback, efficient disaster recovery and simple A/B testing. You should be able to explain this process and draw upon examples of when you have used this previously.

5. How can you prevent the Dogpile effect?

The dogpile effect is a common issue in the development world. A dogpile occurs when the cache expires and websites are affected by numerous client requests simultaneously. The most effective way to prevent this is to use semaphore locks in the cache, which will automatically generate a new value to the cache when it expires.

If you’re in need of more interview tips and tricks, check out our guide to the STAR method to help you best answer these DevOps interview questions, how to ace a video interview and our strengths-based interview advice.

And, if you’re looking to start your career in technology, take a look at our technical graduate programme for more information.