This chapter presents a novel systematic way of building a web-based geographic information system (GIS) running on cloud services. It provides a systematic model to develop and deploy cloud-enabled GIS applications based on a pattern-based architecture. From a more general GIS perspective, works have advocated the creation of spatial cloud computing—a subarea in which the spatiotemporal principles of geoassembling cloud-based GIS spatial sciences, and by extension a well-designed GIS, can be effectively represented in the Cloud given the continuous nature of GIS constraints. Consequently, mainstream information communication technology powerhouses such as Amazon, Microsoft, IBM, Apple, and Google are heavily investing in the provision and support of public cloud infrastructures. Although significant effort has been devoted to migrate generic web-based applications into the Cloud, scant research and development have been put into creating a generic design pattern for a GIS pattern in the Cloud.