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• Basic
• Summary
• Experience
• OSS Contribution
• Talks
• Personal Projects
• Education

• Full-stack engineer with 3+ years of experience in developing web applications, specializing in frontend development
• Proficient in designing and implementing frontend solutions with TypeScript, React, and Next.js
• Strong experience in collaborating with QA teams to design and implement frontend tests
• Focused on web frontend performance optimization and promoting observability best practices
• Expertise in improving CI/CD processes and automating development workflows
• Active contributor to open-source software with a passion for improving software ecosystems

• Languages: HTML, CSS, JavaScript, TypeScript, Rust, Go, Python
• Frontend: React, Next.js, React Aria, Storybook
• Backend: NestJS, Prisma, gRPC, GraphQL, MySQL
• Others: ESLint, Vite, Jest, Playwright, Github Actions, Docker, Kubernetes

• Migrated BFF server from Kotlin to Node.js
• Implemented GraphQL and REST APIs using NestJS and Prisma
• Built foundational tools (lint rules and build tools) to maintain module independence in a modular monolith architecture

Cybozu Office and Mailwise are multi tenant BtoB SaaS products, adopted by over tens of thousands companies in Japan to date.

• Implemented tenant management services essential for the migration
  • Developed a gRPC server and job queue using Go and MySQL

• Optimized CI/CD processes to improve development productivity
  • Reduced CI execution time by over 5 minutes (from 12+ minutes to under 7 minutes)
  • Designed a scalable system to ensure test execution time remains constant as test cases grow
• Established web frontend monitoring infrastructures to reduce bug-fix costs
  • Evaluated the adoption of real user monitoring with Grafana Faro

• Modernized the legacy internal framework with Next.js (App Router)
  • Conducted incremental, page-by-page migration to minimize risk and stability
  • Improved accessibility by implementing UI components using React Aria

kintone is a core product, adopted by one-third of publicly listed companies in Japan and used by tens of thousands of users.

• Led Scrum development as a tech lead for a team of approximately five members
  • Managed the team's roadmap, daily tasks, and overall technical direction
• Modernized the application header from Google Closure Library to React
  • Enhanced accessibility with keyboard navigation and screen reader support
  • Delivered ahead of schedule by adopting a horizontal micro-frontend approach
• Designed a test strategy aligned with the testing trophy and QA member collaboration
  • Prioritized cost-effective tests, including integration tests and visual regression tests
  • Onboarded QA members to contribute to test implementation, reducing testing costs for engineers
• Improved web frontend performance by optimizing the internal UI library
  • Resolved a tree-shaking issue, achieving a bundle size reduction of over 50% across projects

Organization: DeepChem (Open Chemistry)

• Developed a PoC implementation of graph neural network framework for chemistry using JAX (repository: JAXChem)
• Enhanced functionality using Deep Graph Library and PyTorch Geometric
• Improved API documentation and tutorials
• Migration from Travis CI to GitHub Actions
• Automated releases process to DockerHub, PyPI and conda-forge

Final report: https://forum.deepchem.io/t/summary-of-2020-gsoc/249

• Contributed to Chainer Chemistry
• Implemented the graph neural network model for predicting properties of inorganic crystals (MEGNet)
• Enhanced functionalities for benchmark datasets of inorganic crystals

• Developed a mobile app to retrieve and record blood pressure from blood pressure monitors
  • Implemented features using React Native and Bluetooth Low Energy
• Developed a website for doctors to check data stored in a mobile app used by patients
  • Built a single page application using React Native for Web and Redux
• Migrated internal libraries from Flow to TypeScript

I have been passionate about contributing to OSS since I started my career as an engineer. Currently, I mainly contribute to tools related to JavaScript linters and transpilers.

OSS activities: PRs

• Contributions as a core contributor to Biome
  • Implementation of parsers and formatters for new syntax in JavaScript and TypeScript
  • Adding new rules and fixing false positives in linters
  • Led the project to translate the website into Japanese
• Contributions to DeepChem for 3+ months
  • Please refer to Experience section for more details
• In addition to the above, I also have experience contributing to Node.js, ESLint, React Native, SWC, etc.

• Deep dive into Biome at JSConf JP 2023

• Tenbin
  • Tools to minimize the differences in test execution times across shards
• dioxus-free-icons
  • Free icon library for dioxus
  • Created for personal profile site, taking inspiration from react-icons
• babel-plugin-object-to-json-parse
  • Babel plugin that converts object Literal to JSON parse syntax
  • This plugin was featured at ChromeDevSummit 2019 (Tweet and Movie)

• University of Tokyo, Japan (04/2019 - 03/2021)
  • Master of Science in Chemical System Engineering
• Waseda University, Japan (04/2015 - 03/2019)
  • Bachelor of Engineering in Applied Chemistry