Project Overview

Fairshare transforms group expense management by seamlessly connecting to users' banking data through Plaid API integration. This secure connection allows automatic transaction importing, intelligent expense categorization, and simplified bill splitting. Whether you're sharing an apartment with roommates, planning a group vacation, or managing household expenses with family, Fairshare eliminates tedious manual expense tracking and complex calculations. Users can create multiple expense groups, customize splitting rules based on percentages or fixed amounts, and visualize their spending patterns with interactive charts. The platform generates optimized settlement plans that minimize the number of transactions needed to settle debts, making financial reconciliation faster and more efficient.

Key Features

Secure bank account integration through Plaid API for automatic transaction importing

Multiple splitting methods: equal, percentage-based, itemized, or custom amounts

Interactive spending analytics with category breakdown

Real-time balance tracking and notifications

In-app payment reminders and settlement tracking

Expense history with searchable transactions and receipt storage

Challenges Solved

Implementing secure OAuth flow and token management for Plaid API integration

Designing complex database relationships to track multi-party financial obligations

Creating an intuitive expense allocation interface that handles various splitting scenarios

Optimizing database queries for real-time financial calculations and reporting

Building responsive data visualizations that work across device sizes

Technologies Used

TypeScript

Used throughout the application to ensure type safety in financial calculations and data handling, significantly reducing potential for calculation errors in sensitive financial operations.

Bun

Leveraged as our JavaScript runtime for its exceptional speed and built-in tooling, resulting in faster API responses and more efficient transaction processing.

HTMX

Implemented to create a responsive, modern UI while maintaining simplicity. This approach allowed us to deliver dynamic content updates and interactive features without the overhead of a heavy JavaScript framework.

Drizzle ORM

Employed for database operations, providing type-safe queries and migrations that ensure data integrity for financial records and complex expense relationships.

Plaid API

Integrated to securely connect with users' financial institutions, enabling automatic transaction importing, account balance monitoring, and streamlined expense tracking with bank-level security.

Development Process

Research & Financial Analysis

Conducted market research on expense sharing needs and analyzed existing solutions to identify gaps in bill-splitting applications. Studied financial behaviors of roommates, travelers, and families to understand unique requirements.

Plaid API Integration Planning

Evaluated banking API options and selected Plaid for its comprehensive coverage and security features. Designed secure authentication flows and data handling processes compliant with financial regulations.

Data Modeling & Architecture

Created a flexible data model capable of representing complex financial relationships, transaction histories, and customizable expense allocations. Established schema using Drizzle ORM for type safety.

Frontend Development & HTMX Implementation

Built a responsive interface using HTMX to achieve dynamic content updates without the complexity of a full SPA framework. Focused on creating an intuitive UX for financial operations.

Data Visualization & Reporting

Designed interactive charts and reports using Chart.js to provide users with meaningful insights into spending patterns, category breakdowns, and financial trends over time.