Case Study - Payment Gateway

Overview

KangPro isn't a simple directory — it's a complex, dual-natured platform that sits at the intersection of two proven models: the on-demand dispatch of ride-hailing (think Gojek) and the structured merchant listings of a marketplace (think Tokopedia). Tradespeople can advertise their skills, set their rates, and get found — while the platform handles service delivery modes, travel costs, and tiered visibility, all in one coherent system.

The payment layer is the financial backbone of that system. Built on top of the Flip Business API, it handles the full transaction lifecycle — from customer payments through to contractor disbursements — with the reliability and security a two-sided marketplace demands.

We built the payment infrastructure in Ruby on Rails 8, with deliberate choices at every layer: asynchronous job processing via Sidekiq and Redis, asymmetric encryption for payload integrity, IP whitelisting for client access control, and a scheduler-backed status reconciliation system to catch edge cases before they become disputes. Every feature ships with tests. Every change is reviewed. The codebase is built to last.

What we did