— Sensor networks have received wide attention in recent years for their revolutionary impact in numerous fields. To harness their full potential, researchers are beginning to build end-to-end solutions that integrate heterogeneous sensor deployments with traditional networks. While such efforts will bring true value to the use of sensor networks, there are several challenges that need to be kept in perspective. This paper highlights some of the key challenges, and presents a system software methodology to meet the difficult demands of development, deployment and long term management of sensor network systems.