oneSlash Design System

Every time I built a new app, I was reimplementing the same components from scratch. Buttons, navigation, form fields, all over again. So I created oneSlash, a React-based component library that keeps everything consistent across my products.

Design System Document

I built it for my apps, but I wanted others to use it too. So I created a documentation site for anyone building with the library.

oneSlash design system document

Application

Commentify Website

Commentify helps designers, developers, and product managers track comments across collaboration tools. The marketing website runs on the oneSlash design system.

Commentify marketing website

Commentify App

The app itself also runs on the oneSlash design system.

Commentify app

JinhwanKim.com

This portfolio site also runs on it.

Jinhwan Kim personal website

Reflection

Building a design system from scratch taught me the real value isn't in the components — it's in the constraints they enforce. One source of truth now powers three live products: the marketing site, the app, and this portfolio. That shared foundation cut iteration time and kept everything visually consistent without extra effort.