Master Kubernetes concepts including pods, deployments, services, networking, storage, and container orchestration patterns.
Core concepts include pods, deployments, services, ConfigMaps, Secrets, namespaces, ingress controllers, persistent volumes, RBAC, and health checks (liveness/readiness probes). Advanced topics include Helm charts, operators, service mesh, and cluster autoscaling.
It depends on the role. DevOps, SRE, and platform engineering roles require deep Kubernetes knowledge. Backend engineers should understand basic container concepts and how their applications run in K8s. Frontend roles rarely require Kubernetes knowledge.
A pod is the smallest deployable unit (one or more containers). A deployment manages pod replicas, rolling updates, and rollbacks. A service provides stable networking (DNS and IP) to access pods, handling load balancing across replicas. Together they form the core building blocks of K8s applications.
Liveness probes check if a container is running - if it fails, Kubernetes restarts the container. Readiness probes check if a container is ready to serve traffic - if it fails, the pod is removed from service endpoints. Both can use HTTP checks, TCP checks, or exec commands.
An operator is a custom controller that extends Kubernetes to manage complex applications (databases, message queues) using Custom Resource Definitions (CRDs). Operators encode operational knowledge into software, automating tasks like backups, scaling, and upgrades that would otherwise require manual intervention.
Kubernetes uses PersistentVolumes (PV) and PersistentVolumeClaims (PVC) to abstract storage. StorageClasses define provisioning policies. StatefulSets provide stable storage and network identity for stateful apps. Understanding the difference between ReadWriteOnce and ReadWriteMany access modes is important for interviews.