Operators & CRDs Interview Questions

Custom Resource Definition lets you define new API objects to extend Kubernetes with domain-specific resources.

Build an operator when you need automated lifecycle management for complex stateful applications running in Kubernetes.

Use integration tests in kind/minikube, implement leader election, version CRDs carefully, and provide migration paths for upgrades.

Track availability, latency, error rates, resource utilization, and deployment health. Set alerts with runbooks for Operators & CRDs failures and practice incident response so on-call engineers know how to roll back or mitigate.

Store secrets in vaults or CI secret stores, inject at runtime, rotate regularly, and audit access. Avoid committing secrets to git; use sealed secrets or cloud KMS integrations where available.

Keep previous artifacts, use blue/green or canary releases, and automate rollback triggers on error-rate spikes. Operators & CRDs changes should be reversible; test rollback paths in staging before relying on them in production.

Define Operators & CRDs in versioned templates, review changes via pull requests, and apply consistently across environments. Use modules, parameterize environment differences, and run plan/diff before apply.

Read logs and exit codes, reproduce locally, check permissions and network connectivity, and verify dependency versions. Document common failure modes for Operators & CRDs so the team resolves incidents faster next time.

Idempotent operations produce the same result when repeated—critical when scripts or pipelines retry after transient failures. Design Operators & CRDs steps so re-running them does not corrupt state or duplicate resources.

Use the official Kubernetes docs for Operators & CRDs, language or framework references, and reputable community guides. Bookmark release notes and migration guides when upgrading versions, since Operators & CRDs behavior can change between releases.

Copying snippets without understanding why Operators & CRDs works leads to fragile code. Beginners often skip error handling, tests, or edge cases. Slow down, trace execution step by step, and validate assumptions with small experiments.

Name Pods, Deployments, Services, ConfigMaps/Secrets, and Ingress as relevant to Operators & CRDs. Explain how kubectl and YAML manifests express them.

Labels group workloads; selectors bind Services/controllers to Pods. Consistent labeling is required for safe rollouts of Operators & CRDs.

Liveness, readiness, and startup probes with realistic thresholds. Misconfigured probes flap Operators & CRDs traffic during deploys.

kubectl describe/logs/events, check image pulls, probes, quotas, and RBAC. Reproduce with a minimal manifest for Operators & CRDs.

Set requests for scheduling, limits to bound abuse, and watch throttling. Right-size using metrics from Operators & CRDs pods.

Inject non-sensitive config via ConfigMaps; Secrets for credentials with restricted RBAC. Prefer external secret stores for Operators & CRDs in production.

Wrong Service type, missing NetworkPolicies, or assuming ClusterIP is reachable externally. Clarify ClusterIP vs NodePort vs LoadBalancer for Operators & CRDs.

Follow team conventions, split concerns into testable units, handle edge cases, and document assumptions. Review similar modules in the codebase, add observability, and ship incrementally with feature flags if Operators & CRDs is risky.

Watch for bottlenecks, shared state races, config drift, and unbounded resource usage. Load-test Operators & CRDs paths, set limits, and plan horizontal scaling or caching before traffic spikes.