Docker vs Kubernetes - Interview Guide

Docker and Kubernetes solve different but complementary problems. Docker packages applications into containers — lightweight, portable units that include code, runtime, and dependencies. Think of it as creating a standardized shipping container. Kubernetes orchestrates those containers at scale — it handles deployment, scaling, networking, self-healing, and load balancing across clusters. You can run Docker without Kubernetes for simple deployments, but at scale you need orchestration. In my experience, we used Docker for local development and CI builds, then Kubernetes for production where we needed auto-scaling, rolling updates, and self-healing. Our K8s cluster manages 200+ pods across 3 node groups with zero-downtime deployments.