Kaizen To-Do

Desktop task manager built with Java 21 and JavaFX, with a premium interface and clean architecture under the hood.

The case study

Problem: Anyone can write a task CRUD; the hard part is one that looks like a commercial product and is well designed, with no frameworks or database.
Solution: A to-do with priorities, categories, views, light/dark themes and i18n (ES/EN), with the domain at the center and JSON persistence using atomic writes and corruption recovery.
Outcome: A polished, working app that showcases modern Java, JavaFX and clean architecture. MIT licensed.

Process

Development process

The reasoning behind the technical decisions: why each technology was chosen, what challenges came up and how they were solved.

01

JavaFX for a premium UI

I chose JavaFX over Swing because its CSS styling model let me build an interface that feels like a commercial product: light and dark themes, i18n in Spanish and English and careful transitions. The goal was to show that desktop Java can also look modern.
02

The domain at the center

I applied clean architecture: tasks, priorities and categories live in a domain that depends on neither the interface nor the storage. That makes the logic the most stable, testable part, and turns the UI into a replaceable detail.
03

Persistence without a database

To make the app work with zero installation, I store state in JSON. The challenge was integrity: if the program closes mid-save, the data must not corrupt. I solved it with atomic writes (temp file + rename) and corruption recovery, so a valid state always remains.

Repositories