This document summarizes CERN's use of multi-cloud federated Kubernetes to manage distributed computing resources. Some key points: - CERN uses Kubernetes to manage over 210 clusters across 200+ sites and 700,000 CPU cores for high energy physics experiments. - They federated Kubernetes to simplify monitoring and deployment across clusters handling periodic load spikes from conferences and reconstruction campaigns. - CERN integrated their Condor batch system and RECAST analysis platform workloads using Kubernetes federation for uniform APIs, replication, and load balancing across sites.