DevOps Fundamentals

1. What is DevOps?
2. What are the main responsibilities of a DevOps Engineer?
3. Explain the Software Development Life Cycle (SDLC).
4. What is Agile, and how does DevOps work with Agile?
5. What is CI/CD?
6. What is the difference between Continuous Integration, Continuous Delivery, and Continuous Deployment?
7. Walk me through a CI/CD pipeline you have built.
8. What happens after a developer pushes code to GitHub?
9. What tools do you use in your day-to-day work?
10. Describe your typical day as a DevOps Engineer.

Linux, Git & Scripting

1. What Linux commands do you use most often?
2. How do you check CPU, memory, and disk usage on Linux?
3. How do you troubleshoot a Linux server that is running slowly?
4. What is a process, and how do you find or kill one?
5. What is the difference between grep, awk, and sed?
6. What is the difference between git pull and git fetch?
7. What is the difference between git merge and git rebase?
8. How do you resolve a Git merge conflict?
9. What branching strategy does your team use?
10. What Bash or Python automation scripts have you written?

Docker & Kubernetes

1. What is Docker, and why do we use containers?
2. What is the difference between an image and a container?
3. Explain a Dockerfile you have written.
4. What is the difference between CMD and ENTRYPOINT?
5. How do you reduce the size of a Docker image?
6. Explain Kubernetes architecture.
7. What is the difference between a Pod, Deployment, ReplicaSet, and StatefulSet?
8. What is a Kubernetes Service? Explain ClusterIP, NodePort, and LoadBalancer.
9. What are ConfigMaps and Secrets?
10. What is the difference between readiness and liveness probes?
11. What is Ingress, and what does an Ingress Controller do?
12. How does HPA work?
13. A Pod is in CrashLoopBackOff. How would you troubleshoot it?
14. A Pod is in ImagePullBackOff. What would you check?
15. An application is running in Kubernetes but users cannot access it. How would you troubleshoot it?

AWS & Terraform

1. Explain VPC, public subnet, private subnet, route table, NAT Gateway, and Internet Gateway.
2. What AWS services have you worked with?
3. Explain IAM users, roles, and policies.
4. What is EKS, and how have you used it?
5. How would a Pod in EKS securely access S3?
6. What is Terraform?
7. What is Terraform state, and why is it important?
8. What is the difference between terraform plan and terraform apply?
9. What are Terraform modules?
10. How do multiple engineers safely work with the same Terraform state?

Senior / Real-World Questions

1. Tell me about the most serious production incident you handled.
2. A deployment causes 5xx errors immediately after release. What do you do?
3. How do you implement monitoring and alerting for a production Kubernetes application?
4. How have you improved security or reduced AWS costs?
5. Walk me through one project end-to-end—from developer commit to production.

A strong end-to-end question to practice repeatedly is:

Developer pushes code → GitHub → CI → testing → SonarQube → Trivy → Docker build → ECR → CD/GitOps → EKS → Deployment → Pod → Service → Ingress/ALB → DNS → user → monitoring/alerts.

If they can explain that architecture confidently and troubleshoot failures at every stage, they will be much better prepared for mid/senior DevOps interviews.