Top 25 DevOps Interview Questions with Answers

1. How do you set up a CI/CD pipeline using Jenkins?

Install Jenkins and configure Git repository. Then create a job with build triggers and define build steps. Configure post-build actions like deployment using shell scripts or plugins.

2. What command do you use to check the status of a running Docker container?

docker ps shows running containers
docker ps -a shows all containers

3. How do you rollback a deployment in Kubernetes and manage secrets in DevOps workflows?

kubectl rollout undo deployment/<deployment-name>
Tools used: HashiCorp Vault, AWS Secrets Manager, Kubernetes Secrets

4. How do you monitor system performance using Prometheus and Grafana?

Set up Prometheus to scrape metrics from targets, and visualize those metrics using Grafana dashboards.

5. How do you perform blue-green deployment?

Maintain two environments (blue and green). Route traffic to the new version (green), and switch DNS/load balancer when green is validated.

6. How do you configure Git for version control in a DevOps pipeline?

Install Git, clone repositories, create branches, push/pull changes and use webhooks for automation triggers.

7. How do you write a basic Ansible playbook?

Write a YAML file with hosts, tasks, and modules like apt, copy, service to define automation tasks.

8. How do you deploy an application using Helm in Kubernetes?

helm install <release-name> <chart>
Use values.yaml to customize deployment settings

9. How do you create and manage Infrastructure as Code with Terraform?

Write .tf files to define resources. Use terraform init, plan, apply, and destroy for lifecycle management.

10. What would you do if a production deployment fails?

Check logs
Rollback if necessary
Use health checks/alerts
Perform root cause analysis
Prevent recurrence

11. If your Jenkins build is consistently failing, how would you troubleshoot?

Check Jenkins logs
Validate credentials
Inspect pipeline code
Ensure dependent services are up
Re-run with debug logs

12. If a team member accidentally deleted a Kubernetes pod, what’s your next step?

If managed by a Deployment, the pod will be auto-recreated. Otherwise, restore from backup or manually redeploy.

13. How do you implement disaster recovery in a cloud-native environment?

Regular backups
Multi-region deployments
Infrastructure replication
Automated failover
DR drills

14. If your CI/CD pipeline is taking too long, how do you optimize it?

Use parallel stages
Cache dependencies
Break pipelines into micro pipelines
Use smaller containers

15. Explain blue-green vs. canary deployments.

Blue-green: two identical environments, one live
Canary: gradual rollout to a small subset of users before full deployment

16. What do you check if an application is working in staging but failing in production?

Compare environment configs
Check secrets, logs, dependencies
Review Kubernetes manifests or Docker images

17. How do you scale a microservice-based application dynamically?

Configure HPA (Horizontal Pod Autoscaler) in Kubernetes based on CPU/memory metrics or custom metrics.

18. How do you handle a security vulnerability found in a Docker image?

Update base images
Scan with Trivy or Clair
Rebuild and redeploy secure images

19. How would you implement zero-downtime deployment in Kubernetes?

Rolling updates
Readiness/liveness probes
Properly configure replicas and service selectors

20. What do you do if your Terraform state file is corrupted?

Use Terraform state commands to inspect or manually edit the state, or restore from remote backend backup.

21. How do you handle secret rotation in a live system?

Use tools like Vault for auto-rotation. Configure apps to reload secrets via environment variables or mounted volumes.

22. What’s your action plan if you receive high CPU alerts from Prometheus?

Investigate metrics
Check pod/node stats
Correlate with recent deployments
Scale up resources or optimize code

23. Explain the lifecycle of a Jenkins pipeline.

Trigger → Checkout SCM → Build → Test → Deploy → Post-actions → Notify/Alert.

24. How do you recover from a failed Infrastructure deployment using IaC?

Revert .tf or YAML files using version control, re-run the pipeline, or roll back using Terraform or Ansible.

25. Explain GitOps and how it’s different from traditional CI/CD.

GitOps uses Git as the source of truth for infrastructure and app deployment. It enables declarative, auditable, and automated delivery via tools like ArgoCD or Flux.

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Top 25 DevOps Interview Questions with Answers