We propose a novel service-oriented architecture for drone-based multi-package delivery in a skyway network. The proposed architecture provides a high-level design for deploying a skyway network in a city for the effective provisioning of drone services. We propose a graph-based heuristic to reduce the search space for optimal service selection in the skyway network. We then find an optimal solution using the selected drone services under a set of constraints. We conduct experiments to demonstrate the efficiency of our proposed approach.