Payment Gateway

Prerequisite: Familiarity with the concepts introduced in Part 4 — Saga Pattern. Review it first if the terminology in this part is unfamiliar. Answer-first: ISO 20022 MX messages (pacs.008, pacs.009, camt.053) replace legacy ISO 8583 text formats with structured XML/JSON schemas. Production payment gateways validate MX payloads, ensure idempotency, and translate ISO messages to internal ledger events. Series (Part 5 of 8): After designing Saga patterns in Part 4, this article covers the international integration layer — where the Core Banking system communicates with the external financial world via the ISO 20022 standard. ...

Answer-first: Integrating legacy ATM/POS networks (ISO 8583 bitmap protocols) with modern real-time gross settlement systems (ISO 20022 XML/pacs.008 and pacs.009 schemas) requires high-performance Go parser pipelines. In-memory bitwise parsing ensures sub-5ms message translation across payment gateways while preserving full financial audit trails. Prerequisite: Part 4: Modern Event-Driven Core Architecture on event-sourcing structures. Why are international standards important? Answer-first: International messaging standards ensure interoperability across global banking networks, card acquirers, and central bank clearing systems. ...