DevOps Engineer Interview Questions
372 questions across 38 categories
The bulk of a working DevOps engineer's day-to-day: hands-on tooling, common troubleshooting, and the practical judgment calls that come up once you're actually operating systems.
How do requests.memory and limits.memory affect Pod scheduling and node-level eviction behavior differently from each other?
IntermediateKubernetes6 min
How does the Kubernetes scheduler actually decide which node to place a pod on — walk through filtering and scoring?
IntermediateKubernetes6 min
What's the practical difference between node affinity and a plain node selector, given affinity seems strictly more powerful?
BeginnerKubernetes5 min
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
What's the difference between requiredDuringSchedulingIgnoredDuringExecution and preferredDuringSchedulingIgnoredDuringExecution, and what incident does confusing them cause?
IntermediateKubernetes5 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 pod is stuck Pending with an event about its PVC failing to bind — how do you diagnose why?
IntermediateKubernetes7 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
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
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 DaemonSet pod is missing from exactly one node while running fine everywhere else — how do you find out why?
IntermediateKubernetes6 min
A Job is supposed to run to completion exactly once, but it created multiple pods — why, and is that actually a bug?
IntermediateKubernetes6 min
What's actually different at the API level between kubectl rollout restart and deleting all of a Deployment's pods manually?
BeginnerKubernetes5 min
Why does a StatefulSet's rolling update behave completely differently from a Deployment's, and why can that ordering guarantee become a problem mid-incident?
IntermediateKubernetes6 min
How would you build automated alerting specifically for the df/du divergence pattern, rather than relying on someone noticing it during an incident?
IntermediateLinuxPrometheus6 min
df says a server's disk is 100% full, but running du -sh on every top-level directory only adds up to a fraction of that. Where did the rest of the space go?
IntermediateLinux8 min