Technical interview guide

Kubernetes Operators & CRDs

Extending Kubernetes with custom resources and controllers to automate operational knowledge, not just deployment.

Read: 42 min
Practice MCQs: 25
Interview QA: 25
Edition: v3
Editorial status: Reviewed
Relevant for: Platform Engineer

Scope: Kubernetes documentation and apiextensions.k8s.io/v1 behavior current 2026-08-31; verify feature-state notes against the target cluster version.

Interview QA

Treat each question like a live interview question: answer out loud first (structure, assumptions, tradeoffs), then open the model answer to spot gaps and rehearse a tighter follow-up.

Curated: 2026-10-05 · Written: 2026-09-09 · Reviewed: 2026-10-03

QA-1

Design a database operator API.

QA-2

Design an idempotent reconciliation loop.

QA-3

Design spec, status, and conditions for a CRD.

QA-4

Implement safe finalizer cleanup.

QA-5

Handle external resource creation when the response is lost.

QA-6

Version a CRD from v1alpha1 to v1.

QA-7

Choose between a CRD and an aggregated API server.

QA-8

Design CRD validation and defaulting.

QA-9

Secure a multi-tenant operator.

QA-10

Manage child resources without field fights.

QA-11

Handle drift between spec and an external system.

QA-12

Scale an operator to many custom resources.

QA-13

Design operator leader election and failover.

QA-14

Classify reconciliation errors and retries.

QA-15

Design admission for an operator API.

QA-16

Test an operator end to end.

QA-17

Upgrade an operator safely.

QA-18

Recover from a broken conversion webhook.

QA-19

Model a one-shot operation in Kubernetes.

QA-20

Design backup and restore behavior in an operator.

QA-21

Design an operator-controlled application upgrade.

QA-22

Handle deletion and recreation with the same resource name.

QA-23

Observe and alert on operator health.

QA-24

Decide whether to build an operator for a service.

QA-25