Backend Server System Design Based on REST API for Cashless Payment System on Retail Community

Backend is logical space with functional and operations from software applications or information system. One of its implementations is cashless system. The increasing of cashless and electronic payment, and then retail community which not implement it, they must have electronic data capture especially to fullify cashless technology. Through this study we build a system cashless technology as backend server based on REST API. this system can handle some backend process such as top up, and then all of its feature will served in one system which can be accessed from any software platform. In this study, already build data protocol which can be accessed by client application ( frontend ), backend service with login system, register, withdraw, top-up balance with virtual account, top-up from administrator, top-up with bank account, transactions between users, balance information, transaction log, logout and database configuration itself. The backend system is tested for its robustness with 100 API requests carried out in 1 second. The success rate for the entire system is 76.92% of the 13 features offered. Transaction features have a 45% success rate for the process of reducing buyer balance, a 65% success rate for the process of adding seller balance. The top up balance feature reaches 72% and for the withdraw feature has a success rate of 77%.