A lot of online orders in Egypt are still paid in cash, at the door, to a courier. When your platform's money arrives in a courier's pocket instead of through a payment gateway, a delivery app quietly becomes an accounting system. I built the backend for Rahwan , a logistics platform for Egyptian merchants run by Giantrex , where I'm founder and CTO. This post is about the part nobody demos: how the money is tracked between the vendor who sold the product, the courier holding the cash, and ...