sosukesuzuki.dev

Work Experience

  • Anthropic Dec 2025 – present
    Member of Technical Staff

    Working on the Claude Code and Bun JS runtime teams, focusing on Claude Code CLI performance, upstream JavaScriptCore optimizations and bug fixes, and Bun–JavaScriptCore integration.

  • Bun Aug 2025 – Dec 2025
    Systems Engineer

    Worked on upstream JavaScriptCore optimization and bug fixes, and Bun–JavaScriptCore integration. Acquired by Anthropic.

  • Ubie Mar 2022 – Aug 2025
    Product Engineer

    Contributed to product development within a scrum team, worked as a full-stack engineer on a new business, integrated two Next.js applications, and more.

Activities

  • WebKit Feb 2024 – present
    Reviewer (Feb 2025 – present), Committer (Aug 2024 – Feb 2025)

    Working on JavaScriptCore. Merged 600+ patches covering spec-compliance fixes, JIT compiler optimizations, builtin function optimizations, and new ECMAScript feature implementations (e.g., using, import defer).

  • Prettier Sep 2019 – Aug 2025
    Maintainer

    Worked across bug fixes, new feature implementation, code review, issue triage, release blog writing, release management, and shipping releases.

Education

  • University of Tsukuba Apr 2019 – Mar 2025

    B.E. in Information Science