💻Technical Questions
Q1Explain the difference between Docker and Kubernetes.
💡Docker: container runtime. Kubernetes: container orchestration. Docker runs containers; K8s manages, scales, and heals containers across nodes.
Q2What is a Kubernetes pod and how does it differ from a deployment?
💡Pod: smallest unit, one or more containers sharing network/storage. Deployment: manages pod replicas, rolling updates, and rollbacks. StatefulSet vs Deployment.
Q3How does CI/CD work? Describe a pipeline you've built.
💡Code push → build → unit tests → Docker build → push to registry → deploy to staging → integration tests → production deploy. Mention tools: GitHub Actions, Jenkins, GitLab CI.
Q4What is Infrastructure as Code? What tools have you used?
💡Terraform (cloud-agnostic), AWS CloudFormation, Pulumi. Benefits: reproducibility, version control, team collaboration, disaster recovery.
Q5How do you implement zero-downtime deployments?
💡Blue/green, canary, rolling deployments. Health checks, readiness probes in K8s, load balancer draining, feature flags.
Q6Explain how you would set up monitoring and alerting for a production system.
💡Metrics (Prometheus), visualization (Grafana), logging (ELK/Loki), tracing (Jaeger). Alert fatigue — signal vs noise. SLOs, SLAs, error budgets.
🧠Behavioral Questions
B1Tell me about a production outage you helped resolve.
💡Timeline: detection, communication, diagnosis, fix, resolution. Post-mortem culture. What improved afterward.
B2How do you balance velocity (shipping fast) with reliability?
💡Error budgets, SLO-based alerts, feature flags, canary releases, automated rollback. Show you've thought about this tension deeply.
🎯Situational Questions
S1A Kubernetes pod keeps crashing with OOMKilled. What do you do?
💡kubectl describe pod (events), kubectl logs, check resource requests/limits, identify memory leak vs insufficient limits, adjust or fix code.
S2Your team needs to migrate from on-premise to AWS. How do you plan this?
💡Discovery (inventory current state), lift-and-shift vs re-architect, phased migration, cost estimation, DNS cutover strategy, rollback plan.
Must-Know Topics
- ✓Docker & Container Fundamentals
- ✓Kubernetes (deployments, services, ingress, RBAC)
- ✓CI/CD Pipelines (GitHub Actions, Jenkins)
- ✓Infrastructure as Code (Terraform, CloudFormation)
- ✓Cloud Platforms (AWS, GCP, or Azure)
- ✓Monitoring & Observability (Prometheus, Grafana, ELK)
- ✓Networking (DNS, TLS, load balancers)
- ✓Security (secrets management, network policies)
Common Interview Mistakes to Avoid
- ✗Running containers as root user
- ✗Hardcoding secrets in Dockerfiles or manifests
- ✗Not setting resource requests/limits in K8s
- ✗Over-provisioning without right-sizing
- ✗No runbook or documentation for on-call incidents
Frequently Asked Questions
Do I need to know all cloud providers for a DevOps interview?▼
No — know one deeply (AWS is the most common, followed by GCP). Interviewers care about cloud concepts (VPC, IAM, compute, storage, databases) more than cloud-specific CLI commands. Cloud skills transfer across providers.
Is Kubernetes mandatory for DevOps engineer roles?▼
For modern DevOps roles (2025), Kubernetes knowledge is expected at most product companies. At minimum: understand pods, deployments, services, ingress, and config maps. For senior roles: RBAC, network policies, helm charts, and custom controllers.
What scripting languages should a DevOps engineer know?▼
Bash is essential. Python is highly valued for automation, tooling, and scripting. Go is growing for DevOps tooling. You don't need to be a developer, but you should be comfortable writing 50–100 line scripts.
What is the difference between DevOps and SRE?▼
DevOps is a culture/practice. SRE (Site Reliability Engineering, pioneered by Google) is a specific implementation with error budgets, SLOs, and software engineering applied to operations. SRE roles at larger companies (Google, LinkedIn) have more rigorous on-call and reliability engineering expectations.
How do I get DevOps experience without a DevOps role?▼
Set up a personal Kubernetes cluster (kind or minikube), build CI/CD for your side projects (GitHub Actions), deploy to AWS free tier with Terraform, contribute to open-source DevOps tools. A working portfolio is more valuable than certifications alone.
Ready for your DevOps Engineer interview?
Make sure your resume gets you to the interview stage first. Get a free ATS score.
Score My Resume Free →