DevOps Engineer Interview Questions 2026
Questions that test CI/CD pipeline design, infrastructure reliability, and incident response under pressure.
10 questions3 categoriesWith answer hints
Technical
4 questions1What is the difference between blue-green deployment and canary deployment? When would you choose each?
Hint: Blue-green: instant cutover between two identical environments (easy rollback). Canary: gradual traffic shift to new version (catches issues early but slower rollout). Canary is better for high-risk changes.
2Explain how Kubernetes handles pod scheduling and what happens when a node becomes unavailable.
Hint: Scheduler assigns pods based on resource requests, affinity rules, taints/tolerations. On node failure: kubelet stops reporting; node controller marks NotReady; pods rescheduled after tolerationSeconds.
3What is infrastructure as code, and what are the key differences between Terraform and Ansible?
Hint: Terraform is declarative and state-driven for provisioning (cloud resources). Ansible is procedural and agentless for configuration management. They're complementary, not substitutes.
4How does a container differ from a virtual machine at the OS level?
Hint: Containers share the host kernel via namespaces (PID, network, mount) and cgroups for resource limits. VMs run a full OS on a hypervisor. Containers are lighter but have weaker isolation.
Behavioral
3 questions5Tell me about the worst production outage you were involved in. How did you manage communication and resolution?
Hint: Show structured incident response: detection → triage → mitigation → root cause → post-mortem. Highlight communication cadence (status updates every 15 min) and blameless culture.
6Describe a time you identified a significant security or reliability risk before it caused an incident. What did you do?
Hint: Show proactive ownership: what signal alerted you (threat model, code review, alert tuning), how you validated the risk, and how you prioritized and communicated the fix.
7Tell me about a time you had to migrate a critical service with zero downtime. How did you plan it?
Hint: Mention traffic mirroring, dual-write patterns, database migration sequencing, feature flags, and the rollback decision criteria you established before cutting over.
System Design
3 questions8Design a CI/CD pipeline for a microservices application with 30 services that must deploy independently.
Hint: Cover per-service pipelines, artifact registry, environment promotion (dev → staging → prod), change detection to skip unaffected services, rollback triggers, and deployment orchestration.
9How would you design a centralized observability stack for a distributed system?
Hint: Three pillars: metrics (Prometheus/Grafana), logs (Loki or ELK), traces (Jaeger/Tempo). Discuss OpenTelemetry for instrumentation, alert routing (PagerDuty), and SLO/error budget tracking.
10Design a self-healing infrastructure that automatically recovers from common failure modes.
Hint: Cover health checks + readiness probes, auto-scaling groups with lifecycle hooks, circuit breakers at the service mesh layer, automated runbooks via Lambda/Functions, and chaos engineering for validation.
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View DevOps Engineer RoadmapQuestions reflect commonly asked interview topics for DevOps Engineer roles across companies of various sizes. Hints summarize what strong answers typically cover — use them as a preparation guide, not a script.