Payment System Architecture

The payment system is built on a flexible gateway architecture:

Card & Installment Logic:

• Cards filtered based on business rules and basket state

• Installment plans calculated dynamically based on amount

• Support for multi-currency cards

• Bank and card type associations

• BIN number validation for card identification

Stored Card Flow:

• Phone number verification required before card storage

• OTP sent via SMS gateway

• Card tokenization through payment gateway

• Token stored with masked card number

• POS-specific card storage (each gateway has separate tokens)

Gateway Integration:

• Multiple payment gateway support (Garanti, Akbank, etc.)

• Each POS has dedicated gateway configuration

• Saved card gateways mapped to credit card gateways

• Secure token-based card storage

Caching Strategy:

• Phone numbers cached during OTP flow

• Credit card data temporarily cached during save process

• Cache keys include user identifier for security