This is the 5455th most frequent Russian word.
платежной
Relating to payment.
The word 'платежной' is used as an adjective describing the system ('системы') related to payments.
Она работала над улучшением платежной системы.
She worked on improving the payment system.
Here, 'платежной' functions as an adjective modifying 'технологию', indicating the relationship to payments.
Компания внедрила новую платежную технологию.
The company implemented new payment technology.
In this case, 'платежной' describes the card ('карты'), specifying its payment-related purpose.