sequenceDiagram
    participant User
    participant Payment Gateway
    participant Database
    participant Service

    User->>Service: Initiate Payment
    Service->>Payment Gateway: Send Payment Request
    alt Successful Payment
        Payment Gateway-->>Service: Confirm Payment
        Service->>Database: Record Payment
        Database-->>Service: Payment Recorded
        Service-->>User: Payment Success
    else External Payment Failed
        Payment Gateway-->>Service: Payment Failed
        Service-->>User: Payment Failed
    else Database Failure
        Service->>Database: Attempt to Record Payment
        Database-->>Service: Database Error
        Service-->>User: Unable to process payment
    end
    Service->>Database: Commit
    alt Rollback Required
        Database->>Database: Rollback Changes
    end