Over the past decade, Arista Networks has pioneered cloud networking solutions with a unique software-driven approach to building hyper-scale reliable networks. Arista EOS® (Extensible Operating System) developed from the ground-up is a robust, programmable and innovative operating system, with over fifty million ports deployed in the campus, hyperscalers, WAN, and in carrier-cloud environments. This whitepaper discusses how Arista’s EOS architecture provides the foundation to build cloud networks and modern NetDevOps for the next generation of data driven network architectures, based on cloud principles.