Project Overview

The Expense Tracker is a comprehensive financial management application designed to help users monitor their spending habits and maintain budget discipline. This project demonstrates my skills in building practical, data-driven applications with clean user interfaces and secure data storage.

Users can add, categorize, and track expenses over time, view spending patterns through interactive visualizations, and set budget goals. The application persists data securely through Neon PostgreSQL database and authenticates users via Clerk, ensuring users can access their financial information across devices.

Technical Implementation

This project leverages a modern tech stack focused on performance and maintainability, with careful attention to server-side rendering and efficient database operations:

// Example of expense tracking with React Server Components & Neon

// app/expenses/page.js - Server Component
import { auth } from "@clerk/nextjs";
import { sql } from "@vercel/postgres";
import ExpenseList from "@/components/ExpenseList";
import AddExpenseForm from "@/components/AddExpenseForm";

export default async function ExpensesPage() {
  const { userId } = auth();
  
  // Fetch expenses directly from the server
  const { rows: expenses } = await sql`
    SELECT * FROM expenses 
    WHERE user_id = ${userId}
    ORDER BY date DESC
  `;
  
  return (
    

      
Expense Tracker
      
      
    
  );
}

// app/api/expenses/route.js - Server Action
import { auth } from "@clerk/nextjs";
import { sql } from "@vercel/postgres";
import { NextResponse } from "next/server";

export async function POST(request) {
  const { userId } = auth();
  if (!userId) {
    return new NextResponse("Unauthorized", { status: 401 });
  }
  
  try {
    const { amount, description, category, date } = await request.json();
    
    const result = await sql`
      INSERT INTO expenses (user_id, amount, description, category, date)
      VALUES (${userId}, ${amount}, ${description}, ${category}, ${date})
      RETURNING *
    `;
    
    return NextResponse.json(result.rows[0]);
  } catch (error) {
    return new NextResponse("Error creating expense", { status: 500 });
  }
}

Key Features

Challenges & Solutions

Developing the Expense Tracker presented several interesting challenges that required creative problem-solving approaches:

• Efficient data access patterns - Designed optimized database queries to retrieve and aggregate financial data with minimal latency, leveraging the power of Neon PostgreSQL.
• Server component architecture - Carefully designed the component structure to take advantage of React Server Components for data-intensive operations while maintaining interactivity where needed.
• Form validation and security - Implemented comprehensive validation at both client and server levels to ensure data integrity and prevent injection attacks.
• Data security - Implemented comprehensive security measures including Clerk authentication and row-level security in Neon to ensure data isolation between users.

Future Enhancements

While the current implementation delivers on all core requirements, I've identified several opportunities for future enhancement:

• Integration with banking APIs to automatically import transactions
• Machine learning-based categorization of expenses using transaction descriptions
• Recurring expense tracking and future expense prediction
• Budget recommendation engine based on historical spending patterns

Takeaways

This project significantly enhanced my expertise in several key areas:

• Deep understanding of Next.js App Router and React Server Components
• Working with PostgreSQL database design patterns for financial data storage
• Implementing secure multi-user applications with Clerk authentication
• Building performant web applications with an optimal balance of server and client components

The Expense Tracker demonstrates my ability to build practical, user-focused applications that solve real-world problems while maintaining high standards for code quality, security, and performance.