Invoice Builder App

A modern, full-stack web application for creating, managing, and downloading professional invoices. Built with performance and scalability in mind.

What It Does

Invoice Builder helps businesses turn their data into professional invoices with just a few clicks. Perfect for freelancers, small businesses, and finance teams who need reliable invoicing without complexity.

Key Features

• Create Professional Invoices - Build invoices with customer data, line items, and automatic calculations
• Customer & Sender Management - Store and reuse customer and business information
• Smart Calculations - Automatic totals, taxes, and discounts
• PDF Generation - Download beautiful, print-ready invoices
• Status Tracking - Monitor invoice status from draft to paid
• Performance Optimized - Lightning-fast data loading with 87% faster queries

Project Structure

invoice-builder-app/
├── backend/                    # Spring Boot API server
│   ├── src/                   # Java source code
│   ├── docs/                  # Documentation
│   └── README.md               # Backend setup guide
├── frontend/                  # React web application
│   └── invoice-builder-react/ # React + Vite setup
├── docker-compose.yml           # Main Docker configuration
├── docker-compose.dev.yml       # Development overrides
├── docker-compose.prod.yml      # Production overrides
├── .env.example               # Environment variables template
└── README.md                # This file

Tech Stack

Backend

• Framework: Spring Boot 4.0.2
• Language: Java 21
• Database: PostgreSQL 15
• Build Tool: Maven
• ORM: Spring Data JPA with Hibernate
• Migration: Liquibase
• Testing: JUnit 5, Spring Boot Test

Frontend

• Framework: React 19.2.0
• Build Tool: Vite 7.2.4
• Language: JavaScript/TypeScript
• Styling: CSS3 (planned: Tailwind CSS)

DevOps & Infrastructure

• Containerization: Docker & Docker Compose
• Database: PostgreSQL 15 in Docker
• Version Control: Git

Application Modules

Core Business Modules

• Invoice Module - Invoice creation, management, and PDF generation
• Customer Module - Customer data management and relationships
• User Module - User authentication, roles, and access control
• Payment Module - Payment tracking, status, and processing
• Reports Module - Analytics, summaries, and dashboard metrics

Module Integration

• Domain-Driven Design - Clear module boundaries
• API Versioning - Backward-compatible API evolution
• Database Relationships - Proper foreign key constraints
• Security Layers - Module-level access control

Quick Start

Prerequisites

• Docker & Docker Compose
• Git

1. Clone & Setup

git clone <repository-url>
cd invoice-builder-app

2. Environment Configuration

cp .env.example .env
# Edit .env with your secure credentials

3. Start Application

Development Environment:

docker-compose -f docker-compose.yml -f docker-compose.dev.yml up --build

Production Environment:

docker-compose -f docker-compose.yml -f docker-compose.prod.yml up -d --build

4. Access Application

• Frontend: http://localhost:3000
• Backend API: http://localhost:8080/api/v1
• Database: localhost:5432 (internal)
• API Documentation: http://localhost:8080/swagger-ui.html

Docker Operations

Service Management

Start All Services:

docker-compose -f docker-compose.yml -f docker-compose.dev.yml up --build

Start Specific Service:

# Start only backend
docker-compose up backend

# Start only database
docker-compose up postgres

# Start only frontend
docker-compose up frontend

Rebuild Specific Service:

# Rebuild backend only
docker-compose up --build backend

# Rebuild frontend only
docker-compose up --build frontend

# Force rebuild without cache
docker-compose build --no-cache backend

Stop Services:

# Stop all services
docker-compose down

# Stop specific service
docker-compose stop backend

# Remove volumes (clean start)
docker-compose down -v

View Logs:

# View all logs
docker-compose logs

# Follow specific service logs
docker-compose logs -f backend

# View last 50 lines
docker-compose logs --tail=50 backend

Environment Switching

Development to Production:

# Stop development
docker-compose down

# Start production
docker-compose -f docker-compose.yml -f docker-compose.prod.yml up -d --build

Production to Development:

# Stop production
docker-compose down

# Start development
docker-compose -f docker-compose.yml -f docker-compose.dev.yml up --build

Documentation

• Backend Documentation - API details, setup, architecture, and API versioning
• Performance Benchmark - Performance analysis and optimizations
• API Versioning Guide - API evolution and versioning strategy
• Frontend Documentation - UI components and setup

Development

Running Tests

# Backend tests
docker-compose exec backend ./mvnw test

# Performance benchmarks
docker-compose exec backend ./mvnw test -Dtest=SimplePerformanceTest

# Frontend tests
docker-compose exec frontend npm test

Code Quality

• Backend: Lombok for clean code, Spring Boot best practices
• Frontend: ESLint for code quality
• Performance: Optimized database queries with 87% faster loading

Performance Highlights

Our performance optimizations deliver significant improvements:

Feature	Improvement	Impact
Invoice List Loading	87% faster	Better user experience
Memory Usage	59% reduction	Scalable architecture
Database Queries	Optimized projections	Faster response times

See Performance Benchmark for detailed analysis.

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests for new functionality
5. Update documentation
6. Submit a pull request

Support

• Documentation: Check README files in each module
• Issues: Report bugs via GitHub Issues
• Performance: See performance benchmark documentation

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Built for performance, scalability, and maintainability