About Work Links Contact English 日本語

About OKURA Masafumi

As a software developer

I'm a software developer based in Tokyo, Japan. My primary expertise is Ruby and Ruby on Rails.

I've been doing software development for over 10 years and been passionate.

I've been involved mostly in early stage projects, but also interested in improving/fixing legacy codes/apps.

I'm good at using tools such as RSpec and RuboCop with years of experiences.

I like Ruby so much that I've created several gems. Please visit GitHub if you're interested.

My primary focus of development is now on Alba, a JSON serializer for Ruby. It features performance, usability and extensibility. If you're looking for a way to serialize objects into JSON with Ruby, you can try it out.

I use Neovim as my primary text editor and I love it (in fact, I talked about my Neovim usage to over 100 people in tech conference devoted to Vim!)

If you'd like to know more about my development environment, please see my my dotfiles.

As a public speaker

I was a speaker at RubyConf 2021. In 2023 I gave a lightning talk at RubyKaigi, and gave talks at Euruko 2023 and RubyConfTw2023.

I also give talks in various meetups about many topics.

As a community/conference organizer

I'm organizing a few Ruby communities in Tokyo and online: Grow.rb, Entaku.rb and Rubygems Code Reading Meetup.

I'm also a chief organizer of Kaigi on Rails, which started in 2020 as a new tech conference focusing on Web development.

I also was one of the organizers of VimConf 2019 which was successful.


I was born and raised in Japan and I'm a native speaker of Japanese. "OKURA" is my family name and "Masafumi" is my given name: we have family name first and given name last.

I practiced my English in Japan. My TOEIC score was 920 several years ago.

I enjoy brewing coffee. My Instagram account lists my photos on coffee.


Writing Minitest clone at RubyConfTw 2023

Reading RSpec code at Euruko 2023

Lightning talk at RubyKaigi 2023 about Vim and Ruby

On RubyConf 2021 I talked about Ruby method and how to control them.


I joined Roby Rogues a few times.


Hiring / General contact