Invoicing and Expense Tracking SaaS

Full-stack SaaS application for invoicing and expense tracking built with Angular 2, Node.js, Express, and MongoDB Atlas.

Overview

End-to-end full-stack development and architecture of a SaaS application for invoicing and expense tracking, serving small businesses and freelancers.

Role: Full Stack Developer & Architect

Responsible for complete application architecture, from database design to front-end implementation.

Technical Stack

Frontend

Angular 2 with TypeScript
Component-based architecture
Reactive forms for data entry
Material Design components

Backend

Node.js with Express framework
RESTful API design
Authentication and authorization
Business logic implementation

Database

MongoDB Atlas cloud database
Schema design for invoices, expenses, and clients
Indexing for performance optimization
Data aggregation for reports

Key Features

Invoice Management: Create, edit, and send professional invoices
Expense Tracking: Track and categorize business expenses
Client Management: Maintain client database and history
Reporting: Generate financial reports and insights
Multi-user Support: Role-based access control
Cloud-based: Accessible from anywhere with data synchronization

Technical Highlights

Designed and implemented complete REST API
Built scalable database schema with MongoDB
Implemented authentication with JWT
Created responsive Angular components
Set up cloud infrastructure with MongoDB Atlas
Implemented real-time data synchronization

Architecture Decisions

Separated concerns between frontend and backend
Stateless API design for scalability
Document-based data model suited for invoice structure
Component reusability in Angular architecture

Challenges Solved

Complex form handling for invoice creation
Data validation on both client and server
Efficient queries for reporting and analytics
Secure authentication and data protection