/// Personal Finance App Case Study
dompetku
Personal Finance Tracker
Category
Personal Finance App
Stack
Next.js, TypeScript, Tailwind CSS, Prisma, PostgreSQL
Year
2026
01 / The Context
Built With
Live At
https://doompetku.vercel.appPersonal Finance Tracker
Every personal finance app I tried had the same problem: they either demanded my bank credentials immediately, or they were essentially just Excel spreadsheets with a fresh coat of paint.
I built Dompetku ("my wallet") to solve my own problem. I wanted a beautiful, intuitive interface to track expenses and visualize spending habits without surrendering my data to advertisers or paying a monthly subscription.
Crucially, I designed it with a "Continue as Guest" feature so anyone can instantly experience the core value of the dashboard without the friction of creating an account first.
02 / The Problem Space
Defining the core
user pain points.
01
Frictionless Onboarding
Most finance apps lose users at the signup screen. By engineering a fully functional Guest Mode, I allowed users to immediately start logging transactions and visualizing data before ever asking for an email address.
02
Data Privacy Architecture
Trust is everything in fintech. I implemented strict Row-Level Security (RLS) on PostgreSQL and built the app to require zero external bank API connections. Your data is yours.
03
Performant Visualizations
Dashboards get slow when calculating hundreds of transactions. I leveraged React Server Components and optimized Prisma queries to ensure the dashboard renders instantly, maintaining a premium feel.
03 / Strategy & Execution
From hypothesis
to prototype.
1 Week
Designed a modern, clean UI using Tailwind CSS glassmorphism (backdrop blurs) to make financial data feel approachable rather than intimidating.
3 Days
Architected the relational schema in PostgreSQL. Opted for SQL over NoSQL to ensure strict financial ledger integrity.
3 Weeks
Developed the full stack using Next.js and Prisma. Implemented the authentication flow alongside the complex anonymous Guest session logic.
Ongoing
Deployed to Vercel. I now use it daily for my own finances, continuously tweaking the UX based on my own real-world friction points.
04 / Impact & Learnings
Measuring
success.
0
Signup Friction
Thanks to fully functional Guest Mode.
100%
Data Privacy
No bank API lock-in or telemetry.
Daily
Active Usage
I built it for myself, and use it every day.