We propose a novel service-oriented architecture for drone-based multi-package delivery. The proposed architecture provides a high-level design for deploying a skyway network in a city for the effective provisioning of drone-based service delivery. A graph-based heuristic is proposed 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 range of constraints. Experimental results demonstrate the efficiency and effectiveness of our proposed graph-based heuristic approach in terms of execution time and delivery time.