While the Internet of Things (IoT) shows great promise in automating remote monitoring and control applications, programming the sensor nodes to achieve reliable operation remains a difficult task due to firmware complexity. In this talk, we will describe a cloud-driven wireless sensor network (WSN) architecture that virtualizes a multi-hop WSN into a graph tree in the cloud, and all routing and communication functions are performed on the tree. The benefits are reduced firmware complexity, improved reliability, powerful algorithms in the cloud, and easy programming by the users. We will also talk about the challenges in deploying these devices, including impact of harsh environments, influence of governmental regulations, and scaling to 100k+ nodes.