What is DevOps, and why is it important?

DevOps is a set of practices that combines software development (Dev) and IT operations (Ops) to shorten the software development lifecycle (SDLC) while ensuring high quality and reliability.

How does DevOps differ from traditional IT operations?

What are the key principles of DevOps?

1. Collaboration – Breaking silos between Dev & Ops
2. Automation – CI/CD, Infrastructure as Code (IaC)
3. Continuous Integration & Continuous Deployment (CI/CD)
4. Monitoring & Logging – Observability, real-time feedback
5. Security (DevSecOps) – Security integrated into SDLC

Explain the DevOps lifecycle.

1. Plan – Jira, Trello
2. Develop – Git, GitHub
3. Build – Maven, Gradle
4. Test – Selenium, JUnit
5. Release – GitHub Actions, Jenkins
6. Deploy – Kubernetes, Docker
7. Monitor – Prometheus, Grafana

What are some common DevOps tools?

• CI/CD: Jenkins, GitHub Actions, GitLab CI
• Configuration Management: Ansible, Puppet
• Containerization: Docker, Kubernetes
• Monitoring & Logging: Prometheus, Grafana, ELK Stack

What is CI/CD, and how does it work?

CI/CD is a DevOps practice that automates code integration, testing, and deployment.

• Continuous Integration (CI) – Automates code merging & testing.
• Continuous Deployment (CD) – Automates production releases.

Explain the difference between Continuous Deployment and Continuous Delivery.

What is version control, and why is Git used in DevOps?

Version control tracks code changes, allowing collaboration. Git is widely used because of:

• Branching & Merging – Parallel development
• Distributed Version Control – No central dependency

What is Infrastructure as Code (IaC)?

IaC automates infrastructure provisioning using code. Example: Terraform, Ansible, CloudFormation.

How does a DevOps engineer handle configuration management?

Using Ansible, Puppet, Chef, engineers automate configuration setup, ensuring consistency.

What is a container, and how does Docker help DevOps?

A container packages an app with dependencies, ensuring it runs identically anywhere. Docker simplifies container management.

Explain Kubernetes and why it's used in DevOps.

Kubernetes orchestrates containers, automating deployment, scaling, and networking.

What is a microservices architecture?

Microservices break apps into independent, loosely coupled services for scalability and agility.

What is a reverse proxy, and why use Nginx in DevOps?

A reverse proxy (e.g., Nginx) balances traffic, improves security, and caches content.

How do you monitor system performance in DevOps?

Using tools like Prometheus, Grafana, ELK Stack to track logs, metrics, and alerts.

What is the purpose of logging in DevOps?

Logging helps capture system and application events, allowing developers and operations teams to diagnose issues and improve performance.

• Tools: ELK Stack, Loki, Splunk

What are environment variables, and why are they important in DevOps?

Environment variables store configuration settings (e.g., API keys, DB credentials). They help manage different environments (Dev, QA, Production) without modifying code.

What is a load balancer, and why is it used?

A load balancer distributes traffic across multiple servers to improve availability, reliability, and performance.

• Example: Nginx, AWS ELB

What is a service discovery mechanism in microservices?

Service discovery helps microservices locate and communicate with each other dynamically.

• Examples: Consul, Eureka, Kubernetes Service Discovery

How do you implement error handling in a CI/CD pipeline?

1. Automated Testing – Detects issues early
2. Logging & Monitoring – Alerts and logs errors
3. Rollback Strategy – Deploys a stable version if errors occur