Case study

Bank QR payment gateway

Payment service connecting yard and transport billing to two Thai bank QR payment rails.

FIG.1Payment

Role: Sole developer
Stack: Node.jsFastifySCB APIKBank API
Result: QR payment available at the gate without a cashier.

Problem

Gate and receipt flows needed QR payment with callbacks and inquiry, installed on customer premises.

What I owned

Sole developer

What I built

Integrated SCB and KBank QR create, inquiry, cancel, and callback.
Built Windows service install and uninstall tooling.

System shape

Node.js/Fastify service with schema-validated callbacks, transaction IDs, and timezone-correct timestamps, packaged as a Windows service for on-prem installs.

What changed

QR payment available at the gate without a cashier.