Payment Gateway Development: Architecture & Integration Guide

Payment processing is the backbone of digital commerce. Whether you're building a custom gateway or integrating existing providers, understanding the architecture of secure payment flows is essential.

Payment Flow Architecture

A typical payment flow involves: tokenization of card data, 3D Secure authentication, authorization request to the acquiring bank, and settlement. Each step must be logged, encrypted, and idempotent to prevent duplicate charges.

PCI-DSS Compliance Levels

If you handle card data directly, you need PCI-DSS Level 1 certification. Most companies use tokenization services (Stripe, Adyen) to reduce their PCI scope to SAQ-A, which is significantly less burdensome.