Koin-budget buddy

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  Add expenses

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  History of transactions

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  Dashboard activity

Inspiration

Managing personal finances can feel overwhelming with complicated spreadsheets and scattered statements. Koin was created to make expense tracking intuitive, visually clear, and stress-free.

What it does

Koin is a full-stack personal finance companion that tracks daily expenses, categorizes spending habits, and delivers clear financial analytics with secure Google Authentication.

How we built it

Frontend: Built using Next.js (App Router), React, and styled with Tailwind CSS. Backend & Database: Node.js with API integration and MongoDB/Mongoose for data persistent storage. Authentication: Google OAuth for seamless user sign-in.

Challenges we ran into

Managing consistent currency formatting across dynamic UI updates (e.g., standardizing ₹ INR displays). Organizing real-time financial data visualization while keeping dashboard response times fast.

Accomplishments that we're proud of

Designed a clean, accessible interface that turns complex data into actionable spending insights. Successfully built and deployed a production-ready Next.js App Router structure.

What we learned

Best practices for Next.js App Router API route handlers and server state management. How to balance light/dark theme UX design specifically for financial charts and metric displays.

What's next for Koin-budget buddy

Adding custom monthly budget limits and automated over-spending alerts. Expanding export functionality (PDF/CSV reports) for income tax and accounting tracking.

Built With

• api
• google-gmail-oauth
• mongodb
• nextjs
• react
• tailwind