DevOps Foundation Interview Questions

While some interviewers have their own style of inquiry, most job interviews are structured on a series of questions and answers (including some of the most often-asked behavioural interview questions). Here are some of the most often asked interview questions, along with some of the greatest responses. To begin, here’s some expert advise on how to prepare for your DevOps Foundation interview:

1. What is the necessity for Continuous Integration?

The software quality has increase, and the time taken to provide the product’s features has been considerably lower by implementing Continuous Integration for both development and testing. Since each commit to the share repository is produce automatically and perform against the unit and integration test cases, the development team can find and fix mistakes early on.

2. What is configuration management, and what does it entail?

Configuration management (CM) is essentially the process of handling changes so that the system’s integrity is maintain throughout time. This entails a set of policies, techniques, procedures, and tools for analysing, managing, and tracking change proposals and keeping the necessary documentation. CM assists in the design and development of the program by offering administrative and technical guidance.

3. What is Continuous Testing (CT), and how does it work?

Continuous Testing (CT) is a DevOps phase that entails running automated test cases as part of an automated software delivery pipeline to receive immediate feedback on the quality and validation of business risks associated with the automated build of code developed by developers. This phase will assist the team in continuously testing each build (as soon as the code developed is push), allowing the development teams to receive immediate feedback on their work and ensuring that these issues do not arise later in the SDLC cycle. Due to the lack of manual intervention steps to rebuild the project and run the automate test cases every time changes are made will dramatically speed up the developer’s workflow for developing the project.

4. Can you name a few key performance indicators (KPIs) used to measure DevOps success?

Key Performance Indicators, or KPIs, are a type of metric that measures how well something is working. The following are some of the most commonly used KPIs for measuring DevOps success:

Application utilisation, performance, and traffic are all factors to consider.
Availability of the Application
Requests for volume changes
Tickets for customers
The frequency and duration of successful deployments
Rates of error/failure
Deployment failures
Time to detection in the interim (MTTD)
In the meantime, there is a healing period (MTTR)

5. In DevOps, what is CBD?

Component-Based Development (CBD) is an acronym for component-based development. It’s a one-of-a-kind approach to product creation. Developers are constantly looking for existing well-defined, tested, and verified code components to save them from starting from scratch.

6. What is Resilience Testing, and How does it Work?

Resilience testing is a software method that examines an application’s behaviour in chaotic and uncontrolled situations. It also guarantees that data and functionality are not lost in a breakdown.

7. Could you elaborate on the DevOps pipeline?

A pipeline is a series of automated tasks/processes that the software engineering team defines and follows. DevOps pipeline is a set of tools that enable DevOps engineers and software developers to compile, build, and deliver software code to production settings efficiently and reliably.

8. Can you describe the DevOps notion of “shift left to reduce failure”?

We must first comprehend how the standard SDLC cycle operates to comprehend what this entails. There are two basic sides to the conventional cycle.
The planning, design and development phases are on the left side of the cycle.
Stress testing, production staging, and user acceptance are all part of the right side of the cycle.
Shifting left in DevOps simply means moving as many jobs typically performed at the end of the application development process as possible into the earlier phases. We can see from the graph below that if the shift left operations are follow, the odds of errors occurring later in the application development process are considerably reduce because they would have been discover and solve sooner.

9. Do you know what DevOps post-mortem meetings are?

Post-mortem meetings are conven to discuss what went wrong during the implementation of the DevOps technique. It is expect that the team will arrive at steps that need to be made to avoid future failures when this meeting is held.

10. What is the idea of sudo in the Linux operating system?

Sudo stands for superuser do,’ with the superuser being the Linux root user. It’s a tool for Linux/Unix-based systems that allows users with superuser roles to use root-level system commands.

11. Could you describe Jenkins’ architecture?

Jenkins is built on a master-slave model. When a commit is made to the code, the master fetches the most recent version from the GitHub repository. The master instructs slaves to construct, test, and run test cases and generates test case results. This burden is evenly spread across all slaves.

Jenkins additionally uses several slaves since different test case suites may need to be perform for different environments once the code commits are complete.

12. What is ‘Pair Programming’, and how does it work?

Pair programming is a programming technique in which two programmers collaborate on the same system, design, and code. They follow the “Extreme Programming” rules. One programmer is designate as the “driver,” while the other is define as the “observer,” who regularly watches the project’s progress to identify any additional issues.

13. What is the Blue/Green Deployment Pattern, and how does it work?

A blue-green pattern is continuous deployment, application release methodology that gradually transitions user traffic from an earlier working version of the programme or service to an almost identical new release, both running in production.
The old version of the application would be represent by the blue environment, while the new version would be represent by the green environment.
The production traffic would be gradually migrate from the blue to the green environment, with the blue environment remaining on hold in case of a rollback.

14. What is the Dogpile Effect, and how does it work?

It’s also known as cache stampede, and it happens when massive parallel computing systems using caching mechanisms are put under a lot of stress. When the cache expires (or is invalidate) and many requests are made to the website simultaneously, this is refer to as the event. Implementing semaphore locks in the cache is the most popular means of preventing dogpiling. In this approach, when the cache expires, the first process to acquire the lock generates a new value for the cache.

15. What are the procedures to configure a git repository, so that code sanity checks are perform before any commits are made? If the sanity testing fails, how can you prevent it from happening again?

Sanity testing, often known as smoke testing, determines whether or not it is safe to proceed with the test.
Pre-commit is a hook in the Git repository that is activate just before a commit is made. A simple script may be develop to perform the smoke test that uses this hook.

Other tools, such as lines, can be use to execute the script and provide sanity tests on the changes that will be commit to the repository.

16. How can you ensure a script executes whenever a repository receives new commits using git push?

Depending on when the script must be activate precisely, there are three ways to set up a hand on the destination repository to be run. These tools are known as hooks, and there are three sorts of hooks:

Pre-receive hook: This hook is called before the references are update when submitted commits. This hook ensures that the scripts for enforcing development policies are execute.
Update hook: This hook causes the script to run before any updates. Every time a commit is push to the repository, this hook is called once.

17. What are the various stages of DevOps?

The following are the stages of the DevOps lifecycle:

Plan – A plan for the type of application that needs to be develop should be create first. It’s always a good idea to get a broad understanding of the development process.
Code – The application is coded to meet the needs of the end-user.
Build – Assemble the app by combining the numerous codes created in the previous steps.
The most crucial step in the application development process is testing. If required, test the application and rebuild it.
Integrate – Several separate programmers’ codes are combine into one.

Deploy – The code is place in a cloud environment to be use later. Any new adjustments are verified not to disrupt the operation of a high-traffic website.
If necessary, operations are done on the code.
Monitoring – The performance of the application is kept track of. Changes are made to fit the needs of the end-user.

18. In DevOps, what role does configuration management play?

Allows for the management and modification of numerous systems.
Standardises resource configurations, allowing IT infrastructure to be manage more efficiently.
It aids in the administration and management of several servers while also ensuring the infrastructure’s integrity.

19. Name three key DevOps metrics.

The following are the three most important KPIs:

The average time it takes to recover from a failure is called the meantime to failure recovery.
Deployment frequency – The number of times a deployment takes place.
The number of times a deployment fails is express as a percentage.

20. Explain the concept of “Infrastructure as Code” (IaC) in configuration management.

Configuration, deployment, and automatic provisioning are all managed by code.
Rather than physical hardware configuration, data centres are manage via machine-readable definition files.
Assuring that all of your servers and other infrastructure components are provision consistently and without difficulty.
Managing cloud computing systems, also known as infrastructure as a service (IaaS), is a challenging task (IaaS).

21. How is AWS use to implement IaC?

Begin by discussing the age-old processes of entering commands into script files and testing them in a separate environment before deployment and how IaC is replacing this approach. IaC allows developers to build, test, and descriptively manage infrastructure entities using formats such as JSON or YAML, similar to the scripts provided for other services. Infrastructure updates can be develop more easily and deploy more quickly.

22. Can you describe the DevOps notion of “shift left to reduce failure”?

Shifting left is a DevOps concept for enhancing security, performance, and other aspects. Consider this: if we examine all of the DevOps processes, we can conclude that security is test before deployment. Using the left shift method, we may add security to the development phase on the left. [This will be shown in a diagram] We can integrate with all phases, not just development, including before and during testing. This is most likely to increase security by finding flaws early on.

23. What is Continuous Testing, and how does it work?

Continuous Testing performs automated tests as part of the software delivery pipeline to offer real-time feedback on the business risks in the most recent release. Every build is continuously tests to avoid problems with step-switching in the Software delivery life-cycle and allow Development teams to receive rapid feedback. This results in a huge gain in a developer’s productivity because all tests no longer need to be re-run after each update and project re-building.

24. What is the Blue/Green Deployment Pattern, and how does it work?

This is a common way of continuous deployment to reduce downtime. This is where data is sent from one instance to the next. We must replace the old code with a new code version to include a new version of the code. The new version is set in a green setting, while the old one is set in a blue one. After making changes to the previous version, we’ll need to create a new instance from the old one to run the newer version.

25. What is Automation Testing, and how does it work?

Manual testing vs test automation The process of automating a manual method to test an application or system is known as automation. Automation testing comprises stand-alone testing technologies to create test scripts that can be run repeatedly without requiring human intervention.

26. How can testing be automate in the DevOps lifecycle?

All source code updates must be commit to a common DevOps repository by developers. When a change is made to the code, Jenkins-like Continuous Integration tools will fetch it from this share repository and deploy it for Continuous Testing, done by Selenium-like tools.

27. What is the significance of continuous testing in DevOps?

Continuous Testing allows you to test any changes to the code right away. This eliminates difficulties like quality issues and releases delays that might arise when big-bang testing is postpone until the end of the cycle. Continuous Testing provides for higher-quality and more frequent releases in this way.

28. Distinguish between a centralised and a distributed version control system (VCS).

Version Control System with Centralized Administration
A central server stores all file versions.
On a local system, no developer has a copy of all files.
If the project’s central server fails, all of the project’s data will be lost.
System of Distributed Control
On their computers, each developer has a copy of all code versions.
Allows team members to operate offline and eliminates the need for backups stored in a single location.
Even if the server crashes, there is no danger.

29. What exactly is a Git stash?

A developer working on one branch wants to transition to another to work on something different, but they don’t want to submit modifications to your incomplete work. Git stash is the solution to this problem. Git stash puts your updated tracked files on a stack of unfinished modifications that you can reapply whenever you want.

30. Explain how to use Git’s branching feature.

You’re working on an app, and you’d like to add a new feature to it. You can make a new branch and work on the new functionality there.

You always work on the master branch by default.
The circles on the branch represent the branch’s various commits.
You can merge it with the main branch once you’ve finished all the changes.