Yamagishi Kazutoshi is a highly skilled Software Developer based in Japan.

He specializes in full-stack web application development, mastering multiple languages including JavaScript (TypeScript), Ruby, and Go, with deep expertise in React and Ruby on Rails. He is also proficient in cloud infrastructure (AWS and Google Cloud).

Yamagishi is an active contributor to the open-source community, holding committer roles in notable projects:

• He has served as a Committer for Mastodon since 2017, contributing to bug fixes and Japanese localization.
• He is the developer of Manael, an open-source, Go-based reverse proxy application focused on image conversion.
• He also leads the non-profit group Haneru Developers, developing and operating web services using modern architecture.