Top 15 DevOps Interview Questions

Estimated reading time: 8 minutes

The market share for DevOps is projected to grow by $6.6 billion by 2022. This is an indicator of the growing interest in the DevOps approach to software development. Of the companies that were surveyed, 68% agreed to DevOps leading to better business performance and ROI, 47% significantly reduced time-to-market for software and services, and 68% improved overall customer experience. DevOps, which stands for development and operations, is a methodology that encompasses best practices, tools, and technologies that enable the development, testing, and deployment of software in a continuous automated fashion.

DevOps is also a culture and way of thinking that breaks down silos in which IT operations and development functions were traditionally enclosed to create a transparent collaborative software development environment. Because DevOps enables organizations to respond to an ever-evolving technology landscape, some businesses still struggle with DevOps implementation. This means that as more companies endeavor to implement DevOps practices, DevOps engineers should constantly build their knowledge and experience through DevOps Online Bootcamp, training, refresher courses, practical projects, and more to remain updated and relevant.

Top 15 DevOps Interview Questions

More than acquiring knowledge, DevOps engineers need to demonstrate their skills and competence in DevOps-related roles to present themselves as the ideal candidates for the organizations that they intend to work for.

1. What are the core benefits of DevOps?  

Key benefits of DevOps in software development are:

• Faster development cycle
• Faster time-to-market of software or feature deliveries
• Enhance efficiency and productivity due to elimination of the gap and enhanced collaboration between development and operations
• High-quality software
• Faster and easier adaptability to changes in software requirements
• Improved customer experience

2. Explain CAMS in DevOps

CAMS is an acronym for Culture, Automation, Measurement, and Sharing which was advanced by Johns Willis and Damon Edwards who were pioneers of the DevOps approach to software development. It represents the core concepts of the DevOps approach.

3. List some important DevOps KPIs

DevOps key performance indicators help to measure the performance of DevOps teams, identify and fix issues. Top DevOps KPIs are: 

• Cycle time: Reduced amount of time it takes to develop a feature or application.
• Lead time: Faster deployments into the production environment
• Change volume: Faster incorporation of code changes into the production
• Minimizes risks in software quality, security, and compliance
• Mean time to recovery (MTTR): Reduce the average time it takes to recover from deployment failure
• Deployment frequency: Increased deployments within a specified period of time
• Change failure rates: Reduced number of failed deployments

4. What is SSH and what is it used for? 

SSH stands for Secure Shell. SSH is a secured encrypted protocol that allows users to access and control remote servers online using command lines. In DevOps, the SSH protocol facilitates fast, frequent, and automated development and deployments which is the core concept of DevOps.

5. Explain CBD in DevOps

CBD means component-based development. This is an approach to product development that organizes well-defined and tested code components into reusable units. This saves developers the process of having to develop these components from scratch and enables them to deliver consistent and better quality products by simply assembling the reusable code components. 

6. What is configuration management? 

Configuration management is the process of defining and establishing the attributes of software or system in all the environments that host it to ensure that it performs as desired through the changes made to it over time. Here, a configuration platform is used to automate, design, manage, monitor, and control configuration processes to the desired consistent state.

7. What is continuous integration? 

Continuous integration is the practice of continuously integrating code changes from different contributors into a shared repository followed by automated build and test processes. The build process enables development teams to discover issues and address them in time before deploying the product to the end-user. 

8. Explain the phases of the DevOps development life cycle

The phases that software goes through in the development life cycle are: 

• Continuous development. This phase involves planning and coding the software. Planning involves mapping out the vision of the software to be developed and breaking down the project into smaller cycles. Developers then begin to lay out the system infrastructure and write code for the software features.
• Continuous integration. In this phase, developers validate, build, and test code thereafter committing frequent changes to the source code. With every integration of code changes into the source code, the software incorporates new code functionalities.
• Continuous testing. This is a quality analysis stage where the developed software is tested continuously for bugs and errors to ensure optimal functionality and that the software meets the quality specifications and expectations of the end-user.
• Continuous monitoring and feedback. This is where established processes and technologies are used to monitor the software during each phase in the software development life cycle. This ensures continuous reliability and performance of the software in the production environment. Also, this enables the continuous collection of feedback which in turn allows developers to fix software bugs and issues accurately as soon as they are detected. Monitoring should be automated and integrated into the software operations. 
• Continuous deployment. In this phase, new code is deployed continuously into the production environment. Continuous deployment replaces scheduled releases allowing every change that has been merged into the source code and validated to be released to users automatically without affecting the performance of the application.

9. What are the components of selenium?

Selenium is an open-source web application automation testing tool that comes packaged with three components which are: 

• Selenium IDE (Integrated Development Environment)
• Selenium RC (Remote Control)
• Selenium WebDriver
• Selenium GRID

10. What is version control?

Version control, also referred to as source control, is a system that tracks and records software code changes to files in a way that can be recalled later. This allows developers to revert to the previous version in case of a problem. 

11. List the branching strategies that can be used in version control

A branch is a copy of the codebase hence branching is a concept that enables development teams to work collaboratively on different parts of a project without interfering with each other. This way, each team builds its code which is then merged into the codebase. Some branching techniques are:

• Feature branching. Feature branching is done to maintain features in a branch until validated then the feature is merged on the main branch.  
• Task branching. Here the task represents the branch so that certain tasks are connected to the source code.
• Release branching. Release branches are created in preparation for new releases into production.

12. What does it mean to ‘shift left to reduce failure’ in DevOps?

The traditional SDLC cycle phases are divided into two sides. The left side has the planning, design, and development phases, while the right side has the testing, production staging, and user acceptance phases. 

Shifting left in DevOps means is an approach used to prevent defects, improve quality, and test code early in the development process. Thus, shifting left means shifting most tasks usually undertaken at the end of the development cycle to the initial stages. This minimizes errors that come up towards the end of the development process which often requires more resources to fix and increases time-to-market.

13. What is infrastructure as a code (IaC)? 

Infrastructure as a code (IaC) perceives and manages infrastructure including networks, virtual machines, and others in the same way as a code using configuration files. For this reason, IaC has often been referred to as programmable infrastructure.

14. Explain the Dogpile effect and how it can be avoided

Often, caching is used to speed up the performance of web pages. However, where multiple client requests are made at the same time when the cache is expired the web page performance is greatly interfered with and the service can eventually be brought down. This is known as the dogpile effect or cache stampede. 

This effect can be prevented by using the semaphore lock that allows the first client requests to take a lock on the cache element before recalculating new values. This allows only one client request to recalculate the values rather than all of them at the same time.

15. Name some popularly used DevOps tools

Some widely used DevOps tools are:

• Puppet, Chef, and Ansible for configuration management
• Selenium for continuous testing
• Jenkins for continuous integration
• Git for version control
• Docker and Kubernetes for containerization
• Playwright API testing

Conclusion

While DevOps is related and compatible with the Agile methodology, its focus is on the collaboration between development and operations to enhance efficiency in the software development process. DevOps software development methodology yields speed, shorter time-to-market, faster resolution of issues, and iterated incorporation of feedback. This approach has been hailed to deliver high-quality software in line with end-user needs.