Introduction

Introduction to Splitly

  • Splitly is a group expense management and bill-splitting platform that helps users track shared expenses, calculate the amounts to be paid among members, and manage transaction history in a transparent manner.

  • The system is built using a modern web architecture, including a React + Vite frontend, a Node.js/Express backend, and a MongoDB Atlas database. The application is deployed on AWS to take advantage of the scalability, security, and monitoring capabilities of the cloud computing platform.

  • Amazon EC2 is used to deploy the backend API and frontend application, Amazon S3 is used to store invoice and receipt files, and Amazon CloudWatch supports log collection and system status monitoring. Meanwhile, Amazon VPC and Security Groups provide secure network connectivity between the system components.

System Overview

The Splitly system consists of the following main components:

  • Frontend Application

    • Built with React and Vite.
    • Provides a user interface for managing groups, expenses, and settlement statuses.

  • Backend Application

    • Uses Node.js and Express to provide REST APIs.
    • Handles business logic such as group creation, expense management, settlement calculation, and user authentication.

  • Database

    • Uses MongoDB Atlas to store user information, group data, transactions, and payment history.

  • Cloud Storage

    • Amazon S3 is used to store images, electronic invoices, and receipt files uploaded by users.

  • Monitoring & Security

    • Amazon CloudWatch is used to collect logs and monitor the operational status of the system.
    • Amazon VPC, Security Groups, and AWS IAM help control network connectivity and access permissions for AWS resources.

The upgraded architecture improves Splitly’s performance, security, and scalability by separating the frontend and backend.

  • The frontend is stored in Amazon S3 and distributed through Amazon CloudFront.
  • Amazon Route 53 provides domain name management.
  • AWS Certificate Manager provides SSL/TLS certificates for secure HTTPS connections.
  • AWS WAF helps protect the application from suspicious and malicious web requests.
  • The backend continues to run on Amazon EC2 and connects to MongoDB Atlas.

This architecture provides a foundation for scaling the backend and integrating additional AWS services in the future without requiring major changes to the entire system.