DevOps Basic Interview Questions

Here is a list of some common DevOps interview questions along with brief answers for absolute beginners. These questionaries only cover some theoretical topics in DevOps foundation.

1. What is DevOps?

DevOps is a set of practices that combines software development (Dev) and IT operations (Ops) to enhance collaboration and productivity by automating infrastructure, workflows, and continuously measuring application performance. The goal is to improve the speed and quality of software delivery.

2. What are the key principles of DevOps?

The key principles include:

• Collaboration: Breaking down silos between development and operations teams.
• Automation: Automating repetitive tasks to improve efficiency.
• Continuous Integration (CI): Merging code changes frequently and testing them automatically.
• Continuous Delivery (CD): Automatically deploying code changes to production.
• Monitoring and Logging: Tracking application performance and issues in real-time.

3. What is Continuous Integration (CI)?

Continuous Integration (CI) is the practice of automatically integrating code changes from multiple contributors into a shared repository multiple times a day. Each integration is verified by an automated build and tests to detect errors quickly.

4. What is Continuous Deployment (CD)?

Continuous Deployment (CD) is the practice of automatically deploying the code changes that passes automated tests to a production environment. This process helps ensure that new features and bug fixes are delivered quickly and reliably.

5. What are some popular CI/CD tools?

Some popular CI/CD tools include Jenkins, GitLab CI, CircleCI, Travis CI, and Azure DevOps.

6. What is Infrastructure as Code (IaC)?

Infrastructure as Code (IaC) is the practice of managing and provisioning infrastructure through code and automation tools rather than manual processes. This allows for consistent and repeatable environments and is often implemented using tools like Terraform, AWS CloudFormation, or Ansible.

7. What are containers, and how do they differ from virtual machines?

Containers are lightweight, portable units that encapsulate an application and its dependencies, allowing it to run consistently across different environments. They share the host OS kernel but have isolated user spaces. Virtual machines (VMs) include a full OS and virtualized hardware, which makes them more resource-intensive compared to containers.

8. What is Docker in DevOps?

Docker is a platform that enables developers to package applications and their dependencies into containers. In DevOps, Docker is used to create consistent development, testing, and production environments, simplify deployment, and improve scalability.

9. What is Kubernetes, and why is it used?

Kubernetes is an open-source container orchestration platform that automates the deployment, scaling, and management of containerized applications. It is used to manage complex containerized applications and ensure they run efficiently and reliably in production.

10. What is monitoring, and why is it important in DevOps?

Monitoring involves tracking the performance and health of applications and infrastructure in real-time. It is crucial in DevOps for detecting issues, ensuring system reliability, and providing insights for continuous improvement. Tools like Prometheus, Grafana, and Nagios are commonly used for monitoring.

11. What are some common DevOps metrics?

Common DevOps metrics include:

• Deployment Frequency: How often code is deployed to production.
• Lead Time for Changes: The time it takes to go from code commit to production.
• Change Failure Rate: The percentage of deployments that fail.
• Mean Time to Recovery (MTTR): The average time taken to recover from a failure.

12. What is a rollback, and how is it handled in DevOps?

A rollback is the process of reverting an application or infrastructure to a previous state after a failed deployment or change. In DevOps, rollbacks can be managed using version control, deployment strategies (like blue-green deployments), and automated scripts to quickly revert changes and minimize downtime.