Foreign Exchange Payment Processor

A full-stack invoice management application with service fee calculation based on currency.

Tech Stack

• Backend: Spring Boot 4.0.2, Kotlin, PostgreSQL, Flyway
• Frontend: Angular 21, Angular Material, TypeScript
• Database: PostgreSQL 17.2 (Docker)

Prerequisites

• Java 21
• Node.js 25.x
• Maven 3.x
• Docker & Docker Compose
• npm 11.x

Quick Start

1. Start Database

cd backend
docker-compose up -d

Wait for the database to be healthy (check with docker ps).

2. Start Backend

cd backend
mvn clean package
java -jar target/foreign-exchange-payment-processor-1.0.0.jar

Backend runs on: http://localhost:8080

3. Start Frontend

cd frontend/app
npm install
npm start

Frontend runs on: http://localhost:4200

Features

• Create invoices with automatic service fee calculation
• EUR invoices: 0% fee
• USD/GBP invoices: 1% fee (minimum 5 units)
• Paginated invoice history
• Real-time form validation
• Responsive Material Design UI

API Endpoints

• POST /api/invoices - Create invoice
• GET /api/invoices?page=0&size=20 - List invoices (paginated)

Database

The application uses Flyway migrations to set up the database schema and seed initial data. Migrations run automatically on startup.

Development

• Backend: Port 8080
• Frontend: Port 4200
• Database: Port 5432

Database credentials (development only):

• Database: invoice_db
• User: local_user
• Password: local_password