I am watsuyo,
a Frontend Developer.

From Japan 🇯🇵 |
Based in Berlin, Germany 🇩🇪

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About Me

Hi, I am watsuyo, a Berlin-based frontend developer. I specialize in web frontend development, including technologies like React, Vue.js, TypeScript, and Next.js. I also have a strong interest in cloud technologies, particularly Cloudflare.

My expertise extends beyond frontend development. I have experience in Design Systems, project management, and developing tools to improve development efficiency using Python and Shell scripts. I have confident in these areas. Recently, my focus has shifted towards Cloudflare Workers and optimizing web frontends.

Additionally, I actively participate in speaking at events and conferences, as well as authoring books. Please don't hesitate to contact me for speaking opportunities, writing projects, or collaborations on side projects.

Featured Works

Notion RSS Reader

Notion RSS Reader


This is an open-source software (OSS) tool that allows you to save articles from your favorite websites into a Notion Database.

Vue Fes Japan Online 2022

Vue Fes Japan Online 2022


A presentation about migration to Vue 2.7 to enhance safety and development efficiency. It focuses on iCARE, Inc.'s plan to upgrade their Vue 2.6 products to Vue 3, using Vue 2.7 as an intermediate step.

Carely Tech Zine

Carely Tech Zine


An article by iCARE about creating a Notion RSS Reader using TypeScript and GitHub Actions.


Sep 2023 - Present
Frontend Developer | Berlin, Germany
ReactJavaScriptTypeScriptNext.jsTailwind CSSCloudflare Workers
Oct 2020 - Aug 2023
Frontend Developer | Tokyo, Japan
Jan 2019 - Sep 2020
Frontend Developer | Tokyo, Japan