Payments rails
Push vs pull, instant systems, correspondent banking, the Wise model, 3DS step-up. The engineering inside the rails every fintech rides on.
5 hands-on lessons in this topic. Read each one free, then practice it on a real double-entry ledger in the lab.
- Lesson 46
Push vs pull payments
Who initiates the money movement decides who eats the chargeback.
- Lesson 47
Instant payment rails
NIBSS, UPI, Pix, FedNow, RTP, same pattern, different country code.
- Lesson 48
Correspondent banking and Nostro/Vostro
Why a USD wire from Lagos to Singapore goes through three banks that each take a slice.
- Lesson 49
The Wise model: cross-border without correspondent banking
Money never crosses borders. The accounting just makes it look like it did.
- Lesson 50
3D Secure step-up: the ledger pause
When the issuer wants extra verification, the payment is in limbo. Your books need a name for that state.