Ryohei Kameyama

After graduating from university, I founded covelline, LLC in 2013. We are a small team making mobile apps. I am raising my two daughters and developing music composition tools and other experimental software as OSS.

I'm passionate about...

🥽Mixed Reality
📱Mobile Apps
🌐Web technology
🎸Guitar
🤘Progressive Metal

Posts

The Rise of Cohesive Programming — Copy-paste Might be the Future of Frontend

March 25, 2025

Separate your code — that's been the mantra for years. Separate data layer from view layer. Separate logic from UI. Separate styles from markup. But looking at recent frontend development trends, we're moving in the completely opposite direction. What's going on here?

From Twitter App to AI Tools: My Journey with covelline, LLC.

March 24, 2025

From an App Store-topping app to cutting-edge AR/VR solutions, covelline's journey continues with "Eyes" - our patent-pending technology making data truly AI-friendly.

Let's Stop Using the Merge-Branch Pattern

May 3, 2024

The merge-branch pattern is an anti-pattern that can flow into codebases like a river. Let's explore why it's harmful and how to keep our code streams separate.

I spent five years building a web app, posted it on Hacker News, and got my first $1.

February 13, 2022

This is the story of five years spent wandering around the JavaScript tech stack, wasting time, getting lost, and finally taking off.

サイトを Vercel に移行しました

December 1, 2021

今まではレンタルサーバーに PHP を置くという古き良きブログスタイルでした。Vercel と Next.js で、コンテンツは全部 GitHub のリポジトリに入れておくスタイルに移行しました。

Projects

signal

2016 - Present

An open source online MIDI editor. Developed to create a cross-platform MIDI editing environment, powered by WebAudio, WebGL, and WebMIDI. It has a built-in full-scratch SoundFont player, and was built using React and MobX.

ts-wasm-runtime

2018

A zero-dependency WebAssembly parser and runtime built in pure TypeScript.

1D

2017

A graphic design tool with a built-in code editor. It performs mutual conversion between code and graphics. It automatically converts vector graphic operations by mouse or other means to code, and conversely, reactively reflects code changes to graphics.

2D

2017

A visual programming environment for JavaScript that supports Promise and allows you to compose asynchronous programs in a flow-based programming style.