Kubernetes is Google's Borg lessons, rebuilt as an open API.

It won the orchestrator wars because it standardised the interface, not because it was the simplest tool.

2013Docker popularises containersPortable packaging, but no fleet management.

2014Google open-sources KubernetesDistilled from a decade running Borg internally.

2015v1.0 and the CNCFDonated as the first project of a neutral foundation.

2017-18Every cloud ships itEKS, AKS, GKE: managed control planes become normal.

2022Dockershim removedCRI runtimes (containerd, CRI-O) only. Images unchanged.

2023+Gateway API GARole-based routing replaces annotation soup.

Interfaces, not implementations

CRI for runtimes, CNI for networking, CSI for storage. Swap the plugin, keep the YAML.

Declarative API

Everything is an object you apply. Controllers do the work.

Extensible by design

CRDs and operators let any team add new resource types natively.

From Borg to a universal control plane

Kubernetes grew out of Google's internal systems Borg and Omega, which had run production workloads at enormous scale for years. When Google open-sourced it in 2014 and then donated it to the newly formed Cloud Native Computing Foundation in 2015, it gave the industry a vendor-neutral way to describe workloads, which is why every major cloud implemented it.

The reasons it won are architectural. First, it defines stable interfaces for the pluggable parts: how to run a container (CRI), how to network it (CNI), how to give it storage (CSI). The same manifest works across providers because the provider supplies the plugin. Second, the API is declarative, so tools can safely reapply the same desired state. Third, the API is extensible: custom resource definitions let you add new object types that behave exactly like built-ins, which is the foundation of operators.

A frequently misunderstood event: the removal of dockershim in Kubernetes 1.24. Kubernetes stopped talking to the Docker daemon directly and uses CRI runtimes such as containerd. Images built with Docker are OCI images and keep working unchanged. Dates here are approximate milestones; check the release notes of your version for specifics.