Ian Macabulos
Full-Stack Developer
Full-Stack Developer
SubVantage is a comprehensive financial tool built to help users regain control over their recurring expenses. It features a dynamic dashboard that calculates monthly burn and annual forecasts in real-time. The platform supports multi-currency conversion, visualizes spending velocity, and sends intelligent alerts to prevent unwanted renewals.
Explore the live application or review the codebase on GitHub.
A real-time dashboard displaying Monthly Burn, Annual Forecasts, and Total Saved amounts. It helps users understand their immediate financial health at a glance.
Integrated Resend to automate email notifications. Users receive timely alerts 3 days before a subscription renews or a trial expires, helping prevent accidental charges.
Interactive charts powered by Recharts that visualize spending trends over time, helping users identify months with heavy outgoing payments.
The primary challenge was managing state for currency conversions across different subscription cards while ensuring data reliability. Additionally, implementing a notification system that reliably triggers based on server-side dates required careful backend logic.
To ensure the application handles financial data accurately, I moved beyond simple feature building and implemented a robust testing strategy:
Using Vitest, I wrote tests for critical utility functions, ensuring that currency conversion math and date calculations (like "days until renewal") are 100% accurate.
Implemented Playwright to simulate real user flows, such as signing up, adding a new subscription, and verifying that the dashboard updates correctly without manual intervention.
Building SubVantage improved my skills in handling complex data arrays and financial calculations on the frontend. More importantly, integrating Resend and writing E2E tests taught me how to build production-ready applications that are not just functional, but reliable and user-centric.