Personal2024

My App (Expense & Reading Tracker)

Personal Expense, Reading, and Financial Utility Tracker

Live Demo

Role

Full Stack Developer

Year

2024

Team

Solo Project

Tech Stack

Next.js, MySQL, Prisma

A long-running personal project developed continuously to learn new technology stacks—from C to Next.js. The core modules include a reading tracker (books read, reviews, daily pages) and a daily expense tracker with weekly and monthly summaries. The app also expands into shared financial utilities such as monthly subscription splitting with friends, recurring expense tracking, and lending/debt records. The project is designed to keep evolving with additional modules over time.

The Problem

Needed a highly customizable personal tool for both reading habits and financial tracking.
Wanted a system that summarizes behavior and trends—such as daily pages read and weekly/monthly expense overviews.
Aimed to use a single project as a long-term benchmark for engineering growth by progressively upgrading the tech stack.

The Solution

Built the project through three iterations to reflect structured learning and feature expansion.
Version 1 (C / CLI): A command-line application focused on reading logs, strengthening fundamentals in data structures and file/data handling.
Version 2 (PHP / Early Web): An early web implementation that introduced server-side web development, featuring both reading tracking and income/expense recording.
Version 3 (Current / Next.js): A complete rewrite using Next.js, Prisma, and MySQL to adopt modern web architecture and build an extensible modular system (Reading Tracker, Expense Tracker, Subscription Split, Recurring Expenses, Lending/Debt Tracking).

The Result

A practical tool used in everyday life for tracking reading progress and personal spending.
Clear summaries that reveal trends, including daily pages read and weekly/monthly financial overviews.
A single evolving codebase that demonstrates growth—from CLI to legacy web to a modern, scalable web application.

Project Gallery

PC - User interface

Mobile - User interface

Technologies

Next.jsMySQLPrismaLegacy: PHP/CNode.js

Retrospective

Challenges

Designing a database that supports multiple domains (reading, expenses, shared subscriptions, recurring costs, lending/debts) while remaining clear and extensible.
Translating concepts and data across platforms and architectures (CLI → PHP web → Next.js), including changes in data formats and system structure.
Maintaining a scalable code structure over time—module boundaries, naming conventions, and consistent weekly/monthly aggregation logic.
Keeping the UX frictionless for daily logging while presenting summaries that are easy to interpret.

Learnings

Software evolution concepts and how to iteratively grow a system from a minimal version to a richer product.
Key differences between legacy web development (PHP) and modern web development (Next.js), including architecture, state management, and development workflows.
Domain-driven data modeling and query design for efficient weekly/monthly aggregations.
Modern full-stack development with Next.js + Prisma, from project structure and server-side logic to interactive UI and data-driven dashboards.
Building extensible modules—such as subscription splitting and recurring expenses—that can adapt as requirements change over time.