Yoshiya Hinosawa
Software Engineer at denoland
Tokyo, Japan
Summary
🤩
Rockstar🎓
Top SchoolYoshiya Hinosawa is a seasoned software engineer based in Tokyo with 13 years of experience building full-stack web applications, with a strong focus on client-side JavaScript and modern HTML5 APIs. He has shipped frontend systems across startups and enterprise teams, helped operate large-scale CI infrastructure, and contributed core functionality and testing improvements to high-profile open source runtimes like Deno and Node.js. At Deno he worked across JS/TS codepaths, added utilities such as Deno.makeTempDir, and improved build and test tooling—demonstrating comfort in both product-facing UI work and runtime internals. He also improved UX and accessibility on deno.land and maintained code quality in projects like C3.js and the Deno standard library. Equally comfortable refactoring legacy stacks and authoring developer tooling, he pairs pragmatic engineering with a mathematician’s attention to correctness from his Kyoto University background. An avid tinkerer, his current hobby of building a VSCode Custom Editor reflects a continual interest in improving developer experience.
13 years of coding experience
16 years of employment as a software developer
St George InternationalBA, Mathematics, BA, Mathematics at Kyoto University
English, Japanese
Github Skills (26)
javascript10
testing10
typescript10
stream10
typescript-types10
linting10
assert10
nodejs10
typescripts10
d3js10
react10
test-automation10
code-formatting10
deno9
data-visualizations9
Programming languages (25)
Github contributions (5)
c3js/c3
Nov 2013 - Aug 2020
:bar_chart: A D3-based reusable chart library
Role in this project:
Front-end Developer
Front-end DeveloperContributions:47 releases, 1 review, 201 commits in 6 years 9 months
Contributions summary:Yoshiya's contributions focused on addressing linting issues and fixing problems related to the C3.js library's core JavaScript file. They added a `.jshintrc` file to help standardize code style and used it to resolve a number of linting errors within the project. This indicates involvement in maintaining code quality and ensuring consistency within the codebase.
visualizationchartsreactchartsvg
nodejs/node
Nov 2016 - Mar 2025
Node.js JavaScript runtime ✨🐢🚀✨
Role in this project:QA Engineer / Test Automation Engineer
QA Engineer / Test Automation EngineerContributions:1 review, 7 PRs, 15 comments in 8 years 5 months
Contributions summary:Yoshiya primarily contributes to the project by adding and improving test cases within the Node.js repository. Their work focuses on testing stream functionalities such as `PassThrough` and `Transform`, ensuring the correct behavior of these components. They employ techniques like using `assert.strictEqual` and refactoring tests with template strings. The contributions demonstrate a focus on thorough testing and maintaining code quality within the project.
windowsnode-jsjavascriptlinuxruntime
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