Abstract
The development of information technology encourages business actors, including grocery stores, to utilize digital systems in managing sales activities. In general, the process of recording transactions and managing product data is still done manually, which can lead to recording errors, difficulties in managing stock, and delays in generating sales reports. Therefore, a system is needed to assist in managing sales data more effectively and systematically. This study aims to design and develop a mobile-based sales management application using React Native with Firebase as the database. The system design uses several modeling tools, including context diagrams, Data Flow Diagram (DFD) Level 0, DFD Level 1, Entity Relationship Diagram (ERD), and activity diagrams to describe the process flow and data relationships within the system. System testing is conducted using the black box testing method to ensure that each application function operates according to system requirements. The results of this study indicate that the developed application can assist in managing product data, sales transactions, and reports in a more structured and efficient manner, making it easier for store owners to manage sales activities.