This document summarizes the state of Apache Hadoop YARN and its evolution over time. It discusses how YARN started as a sub-project of Hadoop to support multiple applications and long-running services. It then outlines recent initiatives like containerization, GPU/FPGA support, federation, and improved scheduling algorithms to handle larger clusters with tens of thousands of nodes. The document also previews upcoming features in YARN 3.2 and beyond such as node attributes, container overcommit, and auto-spawning of system services.