This project is about building a sports e-commerce platform called Muscle Muffin to support online buying and selling of sports apparel and accessories in an integrated system. The platform aims to solve problems such as inefficient product browsing, unclear transaction flow, and lack of real-time information. Using a web-based architecture, data for users, products, orders, and transactions are managed in a centralized database using MySQL and Flask. The system is developed with HTML, CSS, and JavaScript for the front end, and integrates features such as coupon management, automated email notifications, and the RajaOngkir API for real-time shipping cost calculation. This helps both customers and administrators track orders, manage products, and run the store more efficiently and accurately.