Activity list of Yudai Takada (@ydah)
Index
Works | Talks | Articles | Affiliations | Contributing to conferences | Skills | Certifications | Professional career
Works
Ruby
Committer (2024.12 - present)
- Working on improvements around the Ruby parser.
Lrama
Committer (2024.05 - present)
- Lrama is LALR (1) parser generator written by Ruby. The first goal of this project is providing error tolerant parser for CRuby with minimal changes on CRuby parse.y file.
- Implement Parameterizing rules.
- Implement Inlining.
- Implement Syntax Diagram.
RuboCop RSpec
Maintainer
RuboCop RSpec team (2023.05 - present)
- RSpec-specific analysis for your projects, as an extension to RuboCop.
- I extracted RuboCop RSpec Rails and RuboCop factory_bot from RuboCop RSpec.
Committee
Maintainer (2024.05 - present)
- A collection of middleware to help build services with JSON Schema, OpenAPI 2, OpenAPI 3.
RSpec Sidekiq
Maintainer (2025.07 - present)
- Simple testing of Sidekiq jobs via a collection of matchers and helpers.
RuboCop Capybara
Author/Maintainer (2022.12 - present)
RuboCop factory_bot
Maintainer (2023.05 - present)
- factory_bot-specific analysis for your projects, as an extension to RuboCop.
RuboCop RSpec Rails
Maintainer (2024.05 - present)
- RSpec Rails-specific analysis for your projects, as an extension to RuboCop.
slim-embedded-minify
Author/Maintainer (2023.07 - present)
- A slim file to minify embedded code. Remove comments and unnecessary blank lines in the css or javascript embedding of your Slim files when embedding them in HTML.
slimembedcop
Author/Maintainer (2023.09 - present)
- RuboCop runner for Ruby code embedded in Slim.
RuboCop Committee
Author/Maintainer (2022.12 - present)
rubocop-todo-regenerator
Author/Maintainer (2022.09 - present)
- Custom action to regenerate
.rubocop_todo.ymland create Pull Request.
rubocop-autocorrector
Author/Maintainer (2023.07 - present)
- Custom action to autocorrect rubocop offenses.
redhound
Author/Maintainer (2024.11 - present)
- Pure Ruby packet analyzer. At this time, it is only guaranteed to work on Linux.
railroad_diagrams
Author/Maintainer (2025.1 - present)
- 🛤️ A tiny Ruby+SVG library for drawing railroad syntax diagrams like JSON.org.
Talks
- Yudai Takada: 計算機科学をRubyと歩む 〜DFA型正規表現エンジンをつくる～
北陸Ruby会議01 (2025.12) Slide, Event page - Yudai Takada: Joy with 3D Graphics Using Ruby
RubyConf Taiwan x COSCUP 2025 (2025.08) Slide, Event page, Video - Yudai Takada: 構文解析器入門
PHPカンファレンス関西2025 (2025.07) Slide, Event page - Yudai Takada: LRパーサーはいいぞ
Kernel/VM探検隊@関西 11回目 (2025.05) Slide, Event page, Video - Yudai Takada: Ruby on Railroad: The Power of Visualizing CFG
RubyKaigi 2025 (2025.04) Slide, Event page, Video - Yudai Takada: Dissecting and Reconstructing Ruby Syntactic Structures
RubyKaigi 2025 (2025.04) Slide, Event page, Video - Yudai Takada: Rubyでつくるパケットキャプチャツール
東京Ruby会議12 前夜祭 (2025.01) Slide, Event page - Yudai Takada: 楽しいparse.y
RubyWorld Conference 2024 (2024.12) Slide, Event page, Video - Yudai Takada: 作って理解する RDBMSのしくみ
Kaigi on Rails 2024 (2024.10) Slide, Event page, Video - Yudai Takada: How does Lrama make the Ruby parser grammar G.O.A.T.?
EuRuKo 2024 (2024.09) Slide, Event page, Video - Yudai Takada: The Sequel to a Dream of Ruby Parser’s Grammar
RubyKaigi 2024 follow up (2024.08) Slide, Event page - Yudai Takada: Modular semantic actions
After RubyKaigi 2024 LR Parser Night w/ Asakusa.rb (2024.06) Slide, Event page - Yudai Takada: Kaigi Effect
RubyKaigi 2024 KaigiEffect発表会 (2024.06) Slide, Event page - Yudai Takada: Does Ruby Parser dream of highly expressive grammar?
RubyKaigi 2024 (2024.05) Slide, Event page, Video - Yudai Takada: Extracting from rubocop-rspec
Kyobashi.rb Offline #2 (2024.03) Slide, Event page - Yudai Takada: Ruby Parser Basics
Kyobashi.rb Offline #1 (2024.02) Slide, Event page - Yudai Takada: Menhir is here!
Fukuoka.rb #333 (2023.11) Slide, Event page
Kyoto.rb Meetup (2023.11) Slide, Event page - Yudai Takada: ほんとにあった怖い話「slimに棲むもの」
Kaigi on Rails 2023 (非公式) 前夜祭 (2023.10) Slide, Event page - Yudai Takada: Handle Slim Safety
Osaka RubyKaigi03 (2023.09) Slide, Event page - Yudai Takada: The Labyrinth of How to Write RSpec Pending Reasons
RubyKaigi 2023 AfterParty (2023.06) Slide, Event page - Yudai Takada: Dividing and Managing: The Cops Squad of RuboCop RSpec Dept
RubyKaigi 2023 (2023.05) Slide, Event page, Video - Yudai Takada: Love Ruby, Love Rails, Love ANDPAD
RubyWorld Conference 2022 (2022.11) Slide, Event page, Video - Yudai Takada: Toward a happy symbiosis with RuboCop
RubyKaigi 2022 After Talks (2022.10) Slide, Event page, Video - Yudai Takada: Recommendations for making miscellaneous Custom Cops
Kaigi on Rails _2022_ new (2022.10) Slide, Event page, Video
Articles
- 第14回SmartHR LT大会 兼 忘年会レポート —— 忘年！ 忘年！ 忘年！
SmartHR Tech Blog (2026.01)
https://tech.smarthr.jp/entry/2026/01/22/100000 - Rubyリリース30周年パーティー参加レポート
SmartHR Tech Blog (2026.01)
https://tech.smarthr.jp/entry/2026/01/21/100000 - 北陸Ruby会議01レポート —— みんなとわたしたちのRubyの使い方
SmartHR Tech Blog (2026.01)
https://tech.smarthr.jp/entry/2026/01/20/130000 - 北陸Ruby会議01に登壇します ── わたしたちはRubyをどう使うのか
SmartHR Tech Blog (2025.11)
https://tech.smarthr.jp/entry/2025/11/28/100000 - SmartHRに入社した理由と実際に働いてみて感じたこと —— ydahの場合
SmartHR Tech Blog (2025.11)
https://tech.smarthr.jp/entry/2025/11/26/100000 - 関西Ruby会議08 チーフオーガナイザーの ydah さんにタイムテーブルを解説してもらいました
ANDPAD | TECH BLOG (2025.06)
https://tech.andpad.co.jp/entry/2025/06/24/100000 - 大統一プロダクト間連携を夢見た僕たちが歩いてきた道のりと未来の話をしよう
ANDPAD | TECH BLOG (2024.12)
https://tech.andpad.co.jp/entry/2024/12/24/140000 - アンドパッドはRubyWorld Conference 2024に協賛、登壇します！
ANDPAD | TECH BLOG (2024.12)
https://tech.andpad.co.jp/entry/2024/12/03/120000 - 【令和最新版】カスタムCop 作成 ガイド Ruby 静的解析 RuboCop コードフォーマッタ Linter【AutoCorrect: contextual対応】
ANDPAD | TECH BLOG (2024.12)
https://tech.andpad.co.jp/entry/2024/12/03/100000 - LR Parser Night w/ Asakusa.rb を永和システムマネジメントさんと共催します！
ANDPAD | TECH BLOG (2024.06)
https://tech.andpad.co.jp/entry/2024/06/20/100000 - RubyKaigi 2024 で登壇する hsbt と ydah に聞く Speaker になるまでの道のり
ANDPAD_Engineers Stories (2024.04)
https://en-jp.wantedly.com/companies/andpad/post_articles/900845 - Yudai Takada: Ruby構文解析器 開発日録#2
ANDPAD Advent Calendar 2023 (2023.12)
https://ydah.net/blog/posts/20231224 - Yudai Takada: Ruby構文解析器 開発日録#1
Ruby Advent Calendar 2023 (2023.12)
https://ydah.net/blog/posts/20231223 - Yudai Takada: RuboCopのバージョンを最新に保つための技術
Ruby Advent Calendar 2022 (2022.12)
https://ydah.net/blog/posts/20221219 - Yudai Takada: RuboCop RSpecからRuboCop CapybaraとRuboCop factory_botが切り出されたけど結局どうすればいいの？
ANDPAD | TECH BLOG (2022.06)
https://tech.andpad.co.jp/entry/2023/06/02/100000 - Yudai Takada: RSpec の Request spec をチームで改善していった話
ANDPAD | TECH BLOG (2022.12)
https://tech.andpad.co.jp/entry/2022/12/07/100000 - Yudai Takada: Kaigi on Rails 2022 に弊社のエンジニアが登壇します！
ANDPAD | TECH BLOG (2022.10)
https://tech.andpad.co.jp/entry/2022/10/19/100000 - Yudai Takada: アンドパッド は RubyKaigi 2022 に協賛します！スポンサーブースも出展します！
ANDPAD | TECH BLOG (2022.09)
https://tech.andpad.co.jp/entry/2022/09/07/150206 - Yudai Takada: Rubyでrescueしたらグローバルなオブジェクトを破壊してたよって話
ANDPAD | TECH BLOG (2022.08)
https://tech.andpad.co.jp/entry/2022/08/25/100000
Affiliations
RubyKansai
Member
September 2023 - present
- Ruby Kansai is the primary community for Ruby events in the Kansai region of Japan.
- Chief organizer of OsakaRubyKaigi04, I organized and designed the event.
- Organized OsakaRubyKaigi03, created an event guideline page, and planned and managed LT events. Blog post, GitHub repo
Kyobashi.rb
Co-Founder
January 2024 - present
- Kyobashi.rb is a community where Rubyists from around Kyobashi, Osaka, Japan gather to talk about Ruby and technology.
- Click here for our Slack channel.
- Co-founded the community and organized the meetup.
RuboCop Headquarters
Member of RuboCop RSpec team
May 2023 - present
- The team maintaining RuboCop RSpec and the RSpec Style Guide.
interagent
Member of Committee Maintainers
May 2024 - present
rubyconfig
Member of Maintainers
April 2024 - present
Contributing to conferences
- KansaiRubyKaigi09 Chief Organizer / Designer
https://regional.rubykaigi.org/kansai09/ - SekigaharaRubyKaigi01 Chief Organizer
https://regional.rubykaigi.org/sekigahara01/ - PicoRuby OverflowKaigi Organizer / Designer
https://naniwarb.github.io/picorubyoverflowkaigi/ - KansaiRubyKaigi08 Chief Organizer / Designer
https://regional.rubykaigi.org/kansai08/ - OsakaRubyKaigi04 Chief Organizer / Designer
https://regional.rubykaigi.org/osaka04/ - OsakaRubyKaigi03 Organizer
https://regional.rubykaigi.org/osaka03/ - RubyKaigi 2023 Helper
https://rubykaigi.org/2023/about/
Skills
- Programming languages: Ruby, C, C++, Java, Zig, Python and TypeScript
- Linux Distributions: Ubuntu, CentOS, Debian
- Web backend frameworks: Ruby on Rails, gruf(gRPC) and Django
- Web frontend frameworks: Vue.js(Nuxt.js)
- Database: MySQL, PostgreSQL
Certifications
- Registered Scrum Master™(March 2023-2024)
Professional career
- 令和5年 (2025) 11月 - 現在: 株式会社SmartHR (Product Engineer)
- 令和3年 (2021) 12月 - 令和5年 (2025) 10月: 株式会社アンドパッド (Software Engineer)
- 令和3年 (2021) 8月 - 令和3年 (2021) 11月: 株式会社ソリッドスター (Software Engineer)
- 平成27年 (2015) 4月 - 令和3年 (2021) 7月: 株式会社ソリッドアーツ (Software Engineer)