Multiple-Criteria Decision Analysis (MCDA) is concerned with structuring and taking decisions involving multiple criteria. Integrated with Geographic Information System (GIS) technology, MCDA can be used to select the best locations for any investment project. However, not all investors/clients have the required skills to use these specialized methods and programs. Also, there may be an incompatibility between the consultant and the end user in the end results. Therefore, this research aims to program a web-based Decision Support Engine (DSE) to facilitate the decision-making process and involve the end user easily. The proposed DSE was applied to an E-marketing applied study in Cairo and Giza governorates. Data were collected by electronic questionnaire (928 Questionnaires) processed by SPSS, to create the geodatabase used by the Django web framework to build the DSE. The end result of DSE is producing an Interactive Map to support clients' decision-making in an easy manner. [Bul. Soc. Géog. d'Égypte, 2022, 95: 1-22].