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 the platform that earns the shipping fee.

The problem

Take one order: a 500 EGP product with 50 EGP shipping. The customer pays the courier 550 EGP in cash. At that moment:

the courier is holding 550 EGP that isn't theirs,

the vendor is owed 500 EGP for the product,

the platform has earned 50 EGP in shipping.

None of that money has moved through a bank yet. It moves later, in batches: couriers hand in cash, vendors get paid out.…