tenzyu.com
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Tenzyu

Frontend Engineer

Frontend engineer based in Tokyo, specializing in web applications built with React, Next.js, and TypeScript.

Personal Projects

Personal Website

A Next.js portfolio + blog that reflects my world as an osu! player.

Personal site aggregating osu!-related content (this site).

Motivation: I play osu! as a hobby and stream/post to YouTube, so I built a place to gather it all.

TypeScriptNextJS
osu! bp database

A fast database that can search and aggregate tens of millions of scores across hundreds of thousands of users.

A web app to explore millions of best scores from hundreds of thousands of osu! players in a data table.

Motivation: Many osu! players (myself included) search for maps that maximize Performance Points, so I built a tool to make that easier.

TypeScriptNextJSPostgresDeno
osu! skin remixer

A no-install, browser-based tool to blend game skins intuitively.

A web app to mix osu! skins—customizations for the game UI.

Motivation: There is a culture of cherry-picking favorite parts from different skins to build your own. I wanted to make that beginner-friendly. Existing tools were install-heavy, too coarse or too detailed, outdated, or simply hard to use—so I built one.

TypeScriptNextJS

Professional Experience

Web Development Company
Jan 2024 – Apr 2024

Programmer (Member)

Business: Contract development

Capital: ¥300,000 / Employees: 4 employees (as of Jan 2023)

  • Sales and estimates for contract development projects
  • Internal workflow automation (3 initiatives)
  • Improvements to an OKR management web app
  • Built tooling to streamline sales operations
  • Implemented Slack integration for time tracking
TypeScriptLaravel
Systems Development Company
May 2023 – Jun 2023

Programmer (Member)

Business: Systems development

Capital: ¥3,000,000 / Employees: 2 employees (as of May 2023)

  • Built a new library lending history system for a local school
  • Developed a teacher dashboard
  • Built a student-facing web app for history and book info
TypeScriptReactLaravelPostgreSQL
In-house Service Company
May 2022 – Mar 2023

Programmer (Member)

Business: In-house service development

Capital: ¥32,000,000 (incl. capital surplus, as of July 15, 2025) / Employees: 2 employees (as of May 2022)

  • Built a service that converts UI designs into UI code
  • Agile development
  • Reduced build time from 10 minutes to under 1 minute early on
  • Parsed design objects into AST and generated code via Prettier Doc
  • Implemented Stripe payments
TypeScriptReactCloud FunctionsFirestore

How I Approach Programming

I see the rise of AI in programming as a good thing. I welcome a future where we embrace AI and focus more on solving problems and delivering value.

At the same time, I want to create experiences in entertainment that move people and express new kinds of play through technology. Turning ideas into experiences that surprise users is what motivates me.

I will keep adopting AI and new technologies while pursuing things only I can make—things that help people.

Development Environment

A remote, distributed dev setup centered on NixOS

First edition: July 18, 2025 / Last updated: March 2026