r
    participant Frontend
    participant API
    participant Database
    participant PaymentGateway
    
    User->>Frontend: Browse Products
    Frontend->>API: Request Products
    API->>Database: Query Products
    Database->>API: Return Products
    API->>Frontend: Display Products
    User->>Frontend: Add to Cart
    User->>Frontend: Checkout
    Frontend->>PaymentGateway: Process Payment
    PaymentGateway->>Frontend: Payment Confirmation
    Frontend->>API: Create Order
    API->>Database: Store O