In this paper, we define three of the key issues that need to be solved in order to provide efficient management and configuration of applications and system software in sensor networks: the distribution and management of roles within the network, efficient code distribution algorithms, and efficient on-the-fly code update algorithms for sensor networks. The first issue is motivated by the increasing heterogeneity of sensor network applications and their need for more complex (nonhomogeneous) network topologies and structures. The second one is motivated by the intrinsic energy constraint issues and, in general, the resource limitation of sensor networks. Finally, the third one is needed due to the nature of monitoring applications and optimization needs from applications that should be able to efficiently incorporate code updates so that the network can adapt to its surroundings on the fly. In this paper we present related work and some results for each of these issues as we have dealt with them within the TinyCubus project.