Easy interview questions in DevOps & Cloud, page 5
What are PersistentVolumes and PersistentVolumeClaims for?
A PV is a cluster storage resource the admin provisions; a PVC is a user's request for size and access mode; Kubernetes binds them, decoupling Pods from storage details.
Rolling vs blue/green deployments: differences and trade-offs
Tests risk-cost-downtime judgment. Contrast rolling's gradual swap with blue/green's parallel swap; rolling is cheaper but mixes versions, while blue/green doubles capacity for instant rollback. Red flag: saying blue/green cheaper or rolling double-capacity
Automating a recurring manual cache clear
Recognize the repetitive manual task, document the runbook, then automate it into the deploy pipeline as a post-deploy hook with monitoring.
What happens to volume data when a Pod is deleted?
EmptyDir is tied to the Pod and erased when the Pod is deleted; a PVC-backed PV with Retain keeps the data after the PVC is released for manual recovery.
Explain canary releases and why choose them over rolling updates
This tests risk mitigation via user routing versus in-place replacement. A strong answer defines canary as exposing a subset to the new version first, contrasts rolling updates lacking user segmentation, and cites fast rollback.
Distinguishing toil from necessary ops work
Toil is manual, repetitive, automatable, tactical, and scales with growth; engineering and judgment-heavy work is not toil.
Bind mounts vs named volumes for persisting Docker data?
Persist data outside the writable container layer via a bind mount (a host path you control) or a named volume (Docker-managed under its data dir, portable and the recommended default).
What problem can a breaking API change cause during a rolling update?
Tests if you know rolling updates run mixed versions, so breaking API changes crash cross-traffic. Good answer: note old and new pods serve together, watch probes fail, and monitor 5xx spikes. Red flag: claiming Kubernetes isolates versions during rollout.
Automate temporary elevated database access securely
Self-service request with approval, short-lived auto-expiring grants scoped to least privilege, and full audit logging.
What is Infrastructure as Code?
IaC defines infra in version-controlled files, giving repeatability, peer review, and drift-free consistency, unlike error-prone console clicks.
Automate patching across a VM fleet
Use a patch or config tool to target by tag, roll out in canaried waves with health checks, and prefer immutable golden images long term.
What is SAST and which CI/CD stage integrates it best?
Define SAST as source-code scanning; run it in the test stage on every commit; note early detection is cheapest.
Requests vs limits for CPU and memory?
Requests guide scheduling and reservation, limits cap usage; exceeding a CPU limit throttles the container, while exceeding a memory limit triggers an OOMKill since memory is incompressible.
Committed an API key to Git. Describe two automated CI/CD prevention methods.
This tests layered secret protection in Git workflows. A strong answer names pre-commit scanning and server-side push protection or pipeline scanning. Mention rotating that key. A weak answer only suggests manual review without automated gates.
How do you pin a Pod to nodes with a given label?
The simplest tool is nodeSelector, a key-value map in the Pod spec requiring matching node labels; node affinity is the richer alternative for complex rules.
How do you stop new Pods scheduling on a node?
Kubectl cordon marks the node unschedulable so no new Pods land, while existing Pods keep running; drain is the follow-up that also evicts them.
Attribute cloud costs to teams
Tag resources with team and project metadata, activate them as cost-allocation tags, group the cost report by that tag, and enforce tagging with policy.
Golden signals for capacity planning
Monitor the four golden signals, latency, traffic, errors, and saturation, from day one, watching percentiles and saturation to forecast scaling.
On-Demand vs Reserved vs Spot pricing models
On-Demand is flexible but priciest, Reserved trades a 1-3 year commitment for discounts, Spot is cheapest but interruptible.
What are the four Golden Signals for service health monitoring?
Tests whether you can name the four essential metrics—latency, traffic, errors, saturation—and explain why each matters for detecting user-facing regressions after a release, rather than drowning in infrastructure noise.
We are hiring for this. Every open role lists the topics its interview covers, so you can prepare for the real thing rather than guessing.
See open roles