Kubernetes Interview Questions
128 questions
The most extensive topic on this site: RBAC and security context, storage (PV/PVC/StorageClass), workloads and controllers (Deployments, StatefulSets, DaemonSets, Jobs, CronJobs), autoscaling (HPA/VPA), scheduling and affinity, networking, cluster architecture, CRDs and operators, admission control, and cluster security hardening. Every question is a realistic production scenario — a pod stuck Pending, a webhook silently breaking scheduling, a StatefulSet rollout behaving unexpectedly — not a bare definition.
Why might a pod with a very specific nodeSelector never get scheduled, even though matching nodes exist with capacity?
IntermediateKubernetes6 min
A pod stays Pending with node(s) had untolerated taint — how do you diagnose it and decide toleration vs. removing the taint?
IntermediateKubernetes6 min
How would you troubleshoot a pod stuck Pending even though kubectl describe pod shows no scheduling errors at all?
ExpertKubernetes8 min
What's the difference between requiredDuringSchedulingIgnoredDuringExecution and preferredDuringSchedulingIgnoredDuringExecution, and what incident does confusing them cause?
IntermediateKubernetes5 min
How would you design pod topology spread constraints to keep a Deployment's replicas evenly distributed across availability zones?
AdvancedKubernetes7 min
What's the difference between ReadWriteOnce, ReadWriteMany, and ReadWriteOncePod, and what production symptom does picking the wrong one cause?
BeginnerKubernetes5 min
How would you back up and restore persistent volume data for a stateful app, given kubectl alone doesn't capture volume contents?
IntermediateKubernetes7 min
A CSI driver upgrade causes new attach operations to fail while already-mounted volumes keep working — how do you investigate, and how would you roll this out more safely next time?
ExpertKubernetes8 min
How would you safely expand a PVC for a running StatefulSet without downtime, and what does the StorageClass need to support?
AdvancedKubernetes7 min
A pod is stuck Pending with an event about its PVC failing to bind — how do you diagnose why?
IntermediateKubernetes7 min
Why might mounting the same ReadWriteOnce PVC work for two pods on some clusters but fail on others?
AdvancedKubernetes6 min
A team deletes a PVC expecting the data gone, but it's later recovered from the underlying disk — why, and how should reclaim policy be chosen deliberately?
IntermediateKubernetes6 min
A StatefulSet pod is rescheduled to a new node but its volume won't attach — what's happening, and how do you fix it?
AdvancedKubernetes8 min
How would you design a StorageClass for a high-IOPS database workload versus a cheap-capacity logging workload?
IntermediateKubernetes6 min
A production workload needs persistent storage, and its pods may be rescheduled to different nodes — how do you design storage so data survives that?
BeginnerKubernetes6 min
What does volumeBindingMode: WaitForFirstConsumer actually solve, and what breaks in a multi-zone cluster if you don't set it?
AdvancedKubernetes6 min
How would you set up alerting to catch a CrashLoopBackOff-class issue before it reaches production traffic, rather than discovering it via a user-facing outage?
IntermediateKubernetesPrometheus7 min
A pod goes into CrashLoopBackOff immediately after you roll out a ConfigMap change, but only in one namespace. How do you investigate it?
IntermediateKubernetesContainers10 min
How would your investigation differ if a Pod entered ImagePullBackOff instead of CrashLoopBackOff?
BeginnerKubernetes6 min
How do liveness and readiness probes interact with a Pod that's already crash-looping on startup?
IntermediateKubernetes6 min
How would you decide between a Deployment, a StatefulSet, and a DaemonSet for three different real services (a stateless API, a database, a node agent)?
IntermediateKubernetes6 min
What's the difference between a CronJob's concurrencyPolicy: Forbid and Replace, and what production incident does picking the wrong one cause?
IntermediateKubernetes5 min
A CronJob has been silently creating thousands of failed Jobs over several days — how did this happen, and how would you prevent it?
AdvancedKubernetes7 min
A DaemonSet pod is missing from exactly one node while running fine everywhere else — how do you find out why?
IntermediateKubernetes6 min