Koichi Sasada — 1st Year at Cookpad Q & A

Koichi Sasada has been a core Ruby committer for over 10 years, and joined Cookpad in January 2017 to continue his open source work full-time on Ruby. We caught up with him in our Tokyo office this week to ask what he’s been working on over the last 12 months and what he hopes to achieve in in 2018.

Q: What has been your main focus with Ruby since you joined Cookpad in January 2017?

A: My main duty is improving the performance and quality of MRI (Matz Ruby Interpreter).

There are several of my contributions in the Ruby 2.5.0 release notes: For example, lazy proc creation and removing `trace` instructions. These will improve your rails applications without any modifications. Also Ruby 2.6.0 (development version) contains `Proc#call` performance boost.

On the other hand, we needed to discuss the Ruby 3 specifications. Matz defined 3 goals:

(1) Just-in-Time compiler

(2) new concurrent/parallel execution model

(3) static analysis.

For (1), we are discussing and helping with people who want to implement JIT compilers.

For (2), I’m making new feature as a new concept. Also other developer wants to introduce new concurrent abstraction so we are supporting its introduction.

For (3), we asked Endoh-san (known by @mametter on twitter, he is also known as “transcendental programmer”) to join Cookpad. He is an expert of programming theory and we believe he will make great achievements in this area.

Other than new version development, I spent time to prepare a new CI infrastructure to check bugs. It helps us to find difficult issues and to keep the ruby-trunk clean. I believe This infrastructure will be essential for our drastic changes for Ruby 3.

Other than development, I helped with community activities such as organizing the Ruby25 event (Ruby 25th anniversary event) in Japan and attending Ruby related conferences. Also I keep our close network with academic researchers to discuss about Ruby 3.

Lastly, I planned the Ruby Hack Challenge in Japan to promote Ruby development community activity. RHC introduces basic development process of MRI and attendees can try their own hack on MRI.

Q: What are your key goals in 2018 and for Ruby 3?

A: In 2018, I want to show a prototype of a new concurrency model. Also I’m planning to rewrite the bootstrap mechanism for rapid booting time.

Q: What other languages do you think are most interesting right now in 2018?

A: Now we are working on parallel and concurrent specification for Ruby, so Elixir programming language and Pony programming language are interesting for me. Also Rust programming language I need to study :)

Q: What are the benefits of working at a big Ruby company like Cookpad?

A: Cookpad (and other companies) have huge code bases and we can measure “practical” applications. Additionally, the Ruby programmers’ comments help us a lot.

Q: Do you have any advice for aspiring Ruby committers who want to contribute?

A: Play with our exercises in the Ruby Hack Challenge lecture materials at https://github.com/ko1/rubyhackchallenge and give us your comments and try your own hack. Any questions are always welcome!

Profile: Koichi Sasada

Koichi started developing YARV, a Ruby-specific virtual machine, during his university years. His virtual machine was adopted into Ruby 1.9 in 2007, and since then, he has been engaged in improving the performance of the Ruby interpreter as a core committer through virtual machine optimization and garbage collector rewriting.

After serving as a member of the faculty at the University of Tokyo (2006–2012), he joined Salesforce.com, Heroku, Inc. (2012–2017), then in 2017 he joined Cookpad Inc where he works full-time as a Ruby committer

Koichi has also acted as a Director of the Ruby Association since 2012. Sasada holds a Ph.D. in Information Science and Technology from the University of Tokyo.

Cookpad

Cookpad is the largest recipe sharing community in the world and we believe we can build a better world through encouraging even more people to cook. Cookpad has actively adopted and contributed to open source to help achieve this mission. In 2008, we began to use Ruby, and soon after switched our web platforms to Ruby on Rails, and continue to serve 100 million users per month on the platform

Careers: https://info.cookpad.com/en/careers