Kubernetes (abbreviated k8s) is an open source container orchestrator, launched by Google in 2014 based on its internal experience with Borg, and handed over to the Cloud Native Computing Foundation (CNCF) in 2015.
It automatically deploys, scales and restarts containerized applications across a set of machines. You describe the desired state (how many instances, which resources, which services are exposed) in configuration files, and the control plane continuously brings the actual state back to that desired state.
It is the de facto standard for cloud-native deployment. All major clouds offer it as a managed service (EKS at AWS, GKE at Google, AKS at Microsoft), as do European players such as OVHcloud, Scaleway and Clever Cloud.
Why it matters when hiring
"Kubernetes" on a resume can mean writing a YAML file or running clusters in production. Ask for specifics: who managed the cluster, how many services, which incidents. A strong profile can explain a pod stuck in a restart loop, resource limits, networking and security. The trap: requiring Kubernetes for a small team that does not need it.