Sequence Diagram Updated 4/18/2026

Checkout payment sequence with retry, inventory reservation, and receipt email

This sequence diagram is used to map the checkout path from customer submission through cart validation, card charging, failure handling, inventory reservation, and receipt delivery. It helps teams verify order of operations, error recovery with a retry screen after a failed charge, and service dependencies between Checkout, Payment Gateway, Inventory Service, and Email Service. Product managers, engineers, QA analysts, and solution architects would use it.

sequence diagramcheckout flowpayment retryinventory reservereceipt email
5 nodes 11 connections