Buy Now Pay Later Platform

This repository contains the source code for a simple Buy Now Pay Later platform, which includes multiple microservices and a frontend dashboard.

Table of Contents

• Screenshots and Demo
• Features
• Technologies Used
• Project Structure
• Services
  • API Gateway
  • Credit Service
  • Loan Service
  • Merchant Integration Service
  • User Service
• Frontend
• Setup and Running
  • Docker
  • Docker Compose
  • Viewing Redis Tokens
  • Helpful Commands

Planned Features:

• Send Webhook events to merchants
• Validate API keys upon checkout session creation
• Fraud Detection
• Improve credit underwriting / loan option calculations
• Notification Service
• Update Merchant Dashboard to view all purchases from customers
• Create BNPL Consumer Dashboard to view all loans / make payments

Screenshots and Demo

• You can view screenshots of the platform here.
• A demo video is available TBD.

Features

• BNPL Dashboard:

  • Merchants can create accounts.
  • Create API keys.
  • Set up webhook endpoints.
  • View their customer loans and their status.

• Demo Frontend Sample Shop:

  • Mock checkout process.
  • Creates a checkout session.
  • Backend performs credit underwriting and fraud detection.
  • Issues available loans for the user to select.

Technologies Used

The platform leverages a variety of technologies to deliver a robust and scalable solution:

• Backend:
  • Flask: A lightweight WSGI web application framework.
  • gRPC: A high-performance, open-source universal RPC framework used for communication between microservices.
  • PostgreSQL: Each service has its own PostgreSQL database.
  • Redis: Used for user sessions and caching of data.
  • Rate Limiting: Implemented to control the rate of requests sent or received by the services to ensure fair usage and prevent abuse.
  • JWT Auth: JSON Web Tokens for secure authentication and authorization.
• Frontend:
  • Next.js: A React framework for server-side rendering and static site generation.
  • React: A JavaScript library for building user interfaces.
  • React Hook Form: A library for managing form state in React.
  • React Query: A library for fetching, caching, and updating data in React applications.
  • Material UI: A popular React UI framework.

Project Structure

• backend/
  • api-gateway/
  • credit-service/
  • loan-service/
  • merchant-integration-service/
  • user-service/
• frontend/
  • merchant-bnpl-dashboard/
  • merchant-shop-sample/

Services

API Gateway

The API Gateway handles incoming requests and routes them to the appropriate microservices.

Credit Service

The Credit Service is responsible for handling all credit-related operations within the platform. This includes:

• Credit Underwriting: Assessing the creditworthiness of users applying for loans.
• Credit Scoring: Calculating a credit score based on user data and transaction history.
• Credit Limits: Setting and managing credit limits for users.
• Credit History: Maintaining a record of users' credit transactions and histories.
• Integration with External Credit Bureaus: Mock communicating with external credit bureaus to fetch and update credit information.

Loan Service

The Loan Service handles loan-related operations. This includes:

• Loan Origination: The process of creating new loans, including application, approval, and disbursement.
• Loan Management: Managing the lifecycle of loans, including repayments, interest calculations, and adjustments.
• Loan Repayment: Tracking and processing loan repayments from users.
• Loan Status Monitoring: Monitoring the status of loans to ensure timely repayments and flagging any delinquencies.
• Interest Calculation: Calculating interest on outstanding loans based on predefined rates and schedules.

Merchant Integration Service

The Merchant Integration Service manages merchant-related operations. This includes:

• Merchant Onboarding: Facilitating the process for new merchants to join the platform, including registration, verification, and approval.
• API Key Management: Allowing merchants to generate and manage API keys for integrating their systems with the platform.
• Webhook Management: Enabling merchants to set up and manage webhook endpoints for receiving real-time notifications about transactions and other events.
• Merchant Dashboard: Providing a user-friendly interface for merchants to view and manage their accounts, transactions, and customer loans.
• Transaction Monitoring: Tracking and monitoring transactions initiated by merchants to ensure compliance and detect any anomalies.
• Reporting and Analytics: Offering detailed reports and analytics to help merchants understand their performance and make informed decisions.

User Service

The User Service handles user-related operations. This includes:

• User Registration: Allowing new users to sign up and create accounts on the platform.
• User Authentication: Managing user login and authentication using JWT tokens.
• User Profile Management: Enabling users to view and update their profile information.
• User Session Management: Handling user sessions and ensuring secure access to the platform.
• Password Management: Providing functionality for users to reset and change their passwords.

Frontend

The frontend consists of a merchant dashboard and a sample shop. Users can add items to their cart and then checkout with the BNPL service.

Setup and Running

Docker

Each service has its own Dockerfile. To build and run a service, navigate to the service directory and use the following commands:

docker build -t <service-name> -f <service-name>.dockerfile .
docker run -p <host-port>:<container-port> <service-name>

Docker Compose

To build and run all services together, use Docker Compose:

docker-compose up --build

This will use the compose.yml file to build and start all services.

Viewing Redis Tokens

docker exec -it redis redis-cli -a yourredispassword

Helpful Commands

• docker exec -it db psql -U postgres -d user_service_db
• docker exec -it db psql -U postgres -d api_key_service_db
• \l - view all databases
• \c DATABASE - change to database
• \dt - view all tables for a database