Container orchestration

docker compose is great for one host. For anything bigger, you need an orchestrator. The job of an orchestrator is to decide which container runs on which machine, restart containers that fail, scale them up and down based on load, and give them stable network identities. Kubernetes is the most common, but the concepts apply to all of them.

When do you actually need Kubernetes? When you outgrow a single host. Before that, docker compose or a managed container platform is cheaper and simpler. Kubernetes is a powerful hammer, but small screws do not need it. Reach for it when multiple teams are deploying multiple services at real scale.