Payments Diagrams

Payment systems are among the most protocol-dense areas of software engineering. A single checkout involves a cascade of network calls, cryptographic validations, and state transitions spread across banks, card networks, and third-party processors — all expected to complete in under two seconds and fail gracefully when they don't.

This collection maps the core flows developers encounter when integrating or building payment infrastructure. The Payment Gateway Flow provides the end-to-end overview, while Credit Card Authorization and Payment Capture Flow break down the two-phase auth-and-capture model used by most card networks. Security is covered in depth: 3D Secure Authentication diagrams the cardholder verification step, Fraud Detection Pipeline shows how risk signals are evaluated in real time, and Payment Tokenization explains how raw card data is replaced with opaque tokens to reduce PCI scope.

Recurring revenue flows include Subscription Billing Workflow and Recurring Payment Cycle, while operational concerns like Refund Processing, Chargeback Handling, and Payment Retry Logic cover the failure paths that separate production-ready integrations from demos. Every diagram is free to edit and export directly in Graphlet.