In the context of the rapid evolution of digital technologies and the increasing penetration of e-commerce globally, the relevance of designing effective online store platforms has significantly increased. One of the most critical functions of such systems is inventory accounting, ensuring real-time control of stock levels, transaction recording, and analytics for supply chain optimization. This paper presents the development of an online store prototype, emphasizing both client-facing features (such as catalog Browse and order placement) and backend administrative tools (such as product management and sales reporting). By leveraging the Django framework and PostgreSQL as a robust database engine, the system provides flexibility, scalability, and transparency, allowing it to be tailored to the specific needs of small and medium-sized enterprises. The prototype was validated through functional and integration testing, and the results demonstrated its efficiency, reliability, and extensibility for practical use.