This content originally appeared on DEV Community and was authored by Udoh Deborah
On Day 37, we look at Kubernetes Important Interview Questions & Answers as it’s standard practice through out this challenge.
We are going to look at a number of questions and provide answers for them regarding Kubernetes.
Kubernetes has become the de facto standard for container orchestration, powering cloud-native applications across industries. If you’re preparing for a DevOps interview, Kubernetes is almost guaranteed to show up.
Here are 16 important Kubernetes interview questions with concise answers.
1⃣ What is Kubernetes and why is it important?
Kubernetes (K8s) is an open-source container orchestration platform that automates deployment, scaling, networking, and management of applications. It’s important because it ensures high availability, scalability, and self-healing for modern apps.
2⃣ Difference between Docker Swarm and Kubernetes?
• Docker Swarm → Simple, lightweight, tightly integrated with Docker.
• Kubernetes → Feature-rich, advanced scaling, rolling updates, self-healing, and works across cloud providers.
3⃣ How does Kubernetes handle network communication between containers?
Each pod gets a unique IP. Kubernetes uses a flat network model, allowing pods to communicate directly. For external traffic, Services (ClusterIP, NodePort, LoadBalancer, Ingress) are used.
4⃣ How does Kubernetes handle scaling of applications?
Using Horizontal Pod Autoscaler (HPA), Kubernetes monitors metrics like CPU/Memory and adjusts pod counts automatically.
5⃣ What is a Deployment and how does it differ from a ReplicaSet?
• ReplicaSet → Ensures a specified number of pod replicas are running.
• Deployment → Manages ReplicaSets and allows rolling updates & rollbacks.
6⃣ What are Rolling Updates in Kubernetes?
Rolling updates replace old pods with new ones gradually, ensuring zero downtime.
7⃣ How does Kubernetes handle network security and access control?
Using Network Policies (control pod-to-pod traffic) and RBAC (Role-Based Access Control) for user permissions.
8⃣ Example of a highly available application in Kubernetes?
Running a multi-replica web app behind a LoadBalancer/Ingress, spread across multiple nodes. If one pod or node fails, traffic is routed to healthy pods.
9⃣ What is a Namespace in Kubernetes? Which one is default?
Namespaces logically isolate resources. If not specified, pods are created in the default namespace.
How does Ingress help in Kubernetes?
Ingress manages external HTTP/HTTPS access to services, provides load balancing, SSL termination, and routing rules.
1⃣1⃣ Types of Services in Kubernetes:
• ClusterIP – Default, internal access.
• NodePort – Exposes service via :.
• LoadBalancer – Exposes externally using cloud provider’s LB.
• ExternalName – Maps service to an external DNS name.
1⃣2⃣ Self-healing in Kubernetes?
Kubernetes restarts failed containers, reschedules pods on healthy nodes, and replaces them when deleted. Example: If a pod crashes, Deployment automatically recreates it.
1⃣3⃣ How does Kubernetes handle storage management?
Through Persistent Volumes (PVs) and Persistent Volume Claims (PVCs), allowing containers to use storage independent of the pod lifecycle.
1⃣4⃣ How does NodePort service work?
NodePort exposes a service on every node’s IP at a static port. External traffic can access the service using :.
1⃣5⃣ Single-node vs Multi-node cluster?
• Single-node: Control plane + worker components run on one machine (good for testing).
• Multi-node: Control plane is separate, workloads distributed across worker nodes (production-ready).
1⃣6⃣ Difference between kubectl create and kubectl apply?
• create → Creates new resources; fails if already exists.
• apply → Declarative approach; updates existing resources or creates if not present.
These questions cover the core concepts of Kubernetes and will prepare you for real-world DevOps interviews.
Pro tip: Don’t just memorize—practice these concepts by actually deploying and scaling apps on a Kubernetetes
This content originally appeared on DEV Community and was authored by Udoh Deborah