RubyKaigi 2022: a report from an Evil Martian in Japan


Share this post on


If you’re interested in translating or adapting this post, please contact us first.

Do you know RubyKaigi? RubyKaigi 2022 was recently held in Tsu, Japan, and the entire Evil Martians Japanese office team attended the conference in person. This article is both a first-timer’s report from this awesome Ruby event and is also your chance to get a taste of what the far-east lifestyle is like for Martians engineers!

The Evil Martians from the Japanese office chilling on a couch

The Evil Martians from the Japanese office chilling on our couch

Before we jump in, こんにちは! Since this is the first article from Evil Martians’ Japanese office, a bit of an introduction is in order. In May 2022, we established a new office and fully opened up shop here in Japan. Being here certainly has special benefits for our team. For instance, we’re avid fans of open source and anime (although this is true for the entire Evil Martians crew), but we probably have a much easier time buying obscure anime-related paraphilia from the 80’s here in Osaka than those who are based out of our New York or Lisbon offices.

Usually, we spend our days in Japan writing Ruby and eating gelato, but since our new office is relatively new, RubyKaigi, an annual conference for Ruby programmers held since 2006, was a great opportunity for us to get to know people here in Japan.

Most of us probably know that Ruby was born in Japan, being spawned from the mind of Matz, the benevolent leader of the Rubyist community. Early on—especially in the time before Rails—Ruby was primarily popular in Japan, and while that is no longer the case and its since become an international treasure, Ruby still enjoys popularity in its birthplace.

Heading to RubyKaigi for the first time

This year was my first time going to RubyKaigi. As the previous conference was held way back in 2019, it’s been a while since the last event, so it felt like everyone was excited to meet each other. (Although, it took some time for us to warm up, because, after all, it had been three years since we’d really had this sort of substantial interaction with people offline and in person.)

Sampo gives a thumbs up as he and Andrey ride on a train

Sampo and Andrey speeding towards RubyKaigi

The city of Tsu

RubyKaigi was held in Tsu this year, which is located in Mie prefecture. Fun fact: the station name “Tsu” is the shortest station name in the entirety of Japan. The city of Tsu itself is pretty small too, but we found some excellent restaurants and izakayas there, so it was actually a really nice choice, plus, there was this electrifying feeling, and it felt like the whole city was full of Rubyists. If you went out at night, you could be sure you’d meet others who were into Ruby.

Evil Martians in the land of Ruby

The Evil Martians from the Japanese office pose in front of a RubyKaigi 2022 sign

We arrived!

In the picture above, you can see everyone who works at the Osaka office, and you’ll hear from each of them in this article, too. Ruby Kaigi 2022 also gave us a clear goal: we want to have at least one Martian on the stage in 2023, preferably two!

Digesting some recent Ruby developments

Now, onto the actual meat of the meetup, the talks. There were three that I especially liked.

The first was by Yukihiro “Matz” Matsumoto himself, the creator of Ruby. He gave a talk about the future of Ruby, and it was really interesting to hear about the direction he wants to take the language in.

Also, it was interesting to listen to the discussion between Matz and the Ruby committers and about whether the language should have _1 aliased as it. At first I was with Matz on this issue, but after listening to other people talk about it quite passionately, now I’m starting to see it too. (This would make code like ruby [1, 2, 3].each { puts it } a little bit nicer.)

The second talk I really liked was by Yuji Yokoo, who talked about how he used Ruby to write a presentation/game for the Sega Megadrive. In fact, the presentation itself was running on an actual MegaDrive! This got me really excited about the possibilities of mruby, which is a lightweight implementation of Ruby that can be used on embedded devices—but I had no idea it could run on something as old as the Sega MegaDrive (released in 1988!).

The third talk I really liked was by Samuel Williams, who spoke about the new fiber scheduler that was implemented in Ruby 3.0. What made this talk so exciting was the way Samuel related a story about Ruby being too slow for a real-world use case, a DNS server, and he discussed improving the language enough so that it could be used for this. The future of async Ruby and how async Ruby should be easy to write, was something I can 100% get behind.

Mie was a good place to be; seeing so many people in person after the long pause was cool.

My thoughts: Rubysts really like to rewrite JIT again and again. I think there were around 5 talks about that at the conference. They also like to rewrite GC. It doesn’t look like types have taken off in Ruby world so far. There is a DefinitelyTyped analogue for RBS, but have only been 40+ typedefs for the last few years. But still, a lot people, like Fu-ga, are trying to make it happen. Japanese Rubysts love to functionally use Ruby and they don’t really like boring web development tools like Rails from what I can see. There was also a cool talk from Yuji Yokoo on making Sega MegaDrive games in Ruby. And, Jeremy Evans really likes to tackle esoteric bugs as evidenced by his talk Fixing Assignment Evaluation Order.

There was a sense of excitement at Ruby Kaigi, it felt like everyone was really excited about getting to share their love of Ruby. We saw a talk about how to run mruby on Sega MegaDrive; we also attended a talk about the future of concurrent processing in Ruby and how exciting the world of Falcon and ActiveRecord on Rails 7.1 looks.

The RubyKaigi stage and many RubyKaigi attendees sitting in a large hall, many with laptops

This year’s venue for RubyKaigi

I was pretty excited to attend first in-person RubyKaigi since COVID-19 pandemic started. (And the first big, in-person conference in years). RubyKaigi is still the same wonderful, rare kind of conference that combines a wild selection of hardcore topics and top-class organization—for a more than affordable fee. It was fun, it was weird, it was good. Can’t wait for the next one.

After Ruby Kaigi, I headed to Ise Jingu Shrine with some Ruby friends. It was such a great experience getting to feel the atmosphere of this holy shrine alongside other Rubyists. Plus, the food was great!

Sampo takes a selfie at Ise Jingu Shrine. There are many people walking around at the shrine

Extraordinary experiences are another perk of life in Japan

I got to meet some pretty nice people. Matz even retweeted this photo me and my Ruby friends eating shaved ice!

On the way back to Osaka, I decided to splurge on the premium seat. It was 400 yen more, but I think it was completely worth it. I hope to see you next year in Matsumoto City, Japan, to celebrate Ruby Kaigi 2023!

The first offline RubyKaigi since the pandemic began gave me hope.

Hope that the world will be normal again someday. What’s more, even TRICK was back! More than anything else, this contest demonstrates that Ruby is a hell of a lot of fun! Want to feel again like a kid who just wrote his first HelloWorld program? Check out the jury’s talk. What can I say? “Ruby is dead”. And I’m incredibly happy because that means another RubyKaigi next year.

Finally, there’s no need to wait for more Ruby goodness in Japan; the Evil Martians team really wants to give back and contribute to the Japanese Ruby community as much as we can. On that note, we already look forward to our own Andrey Novikov speaking at the upcoming Kaigi on Rails 2022!

Evil Martians is a product development consultancy with offices around the world, including in Osaka, Japan! We work with startups and established businesses—and we get things done! So, if you have a project in need, get in touch with us!

Join our email newsletter

Get all the new posts delivered directly to your inbox. Unsubscribe anytime.

In the same orbit

How can we help you?

Martians at a glance
years in business

We transform growth-stage startups into unicorns, build developer tools, and create open source products.

If you prefer email, write to us at