ScalaMatsuri blog

This blog is about ScalaMatsuri preparation, and sponsored by Hatena, Inc.

ScalaMatsuri 2023 guide: Tips on making the online conference experience 120% better

Hello! This is omiend from the ScalaMatsuri Chair Team.

ScalaMatsuri 2023 is just around the corner, and we've been busy preparing for the event. We are writing this year's edition of the "120% Fun Participant's Guide" to help you enjoy ScalaMatsuri even more.

We hope you will read it and come to ScalaMatsuri 2023, and we look forward to seeing you at ScalaMatsuri 2023!

What is ScalaMatsuri?

ScalaMatsuri is Asia's largest international Scala conference.

We are very pleased to announce that more than 400 people attended the last ScalaMatsuri in 2022. ScalaMatsuri 2023 will mark the 10th anniversary since its predecessor Scala Conference in Japan 2013 was held!

Schedule is set!

The schedule has been set, finally. We have a lot of great talks this year!

This year's ScalaMatsuri will feature a keynote session by Daniel Spiewak, the well-known author of the Cats Effect, who will speak on 'The Case For Effect Systems.' This will be a 40 minutes from 10:20 JST on Day1 (4/15), so don't miss it!

Program - ScalaMatsuri 2023

Event Schedule

ScalaMatsuri 2023 will be held for two days on Saturday, April 15th (JST), which is Friday 14th night in the US, and Sunday, 16th (JST).


Registration is scheduled to begin at 9:30am JST.


The opening session will start at 10:00am JST, so please prepare Zoom or Discord before then.

Satellite Venue & Networking Event!

We are planning an in-person networking event on the first day! Therefore, to make it easier for everyone to attend, we have decided to set up a "Satellite Venue" since it would be difficult for everyone to move around if the event is held only online.

Note: The talks will be broadcasted in Japanese in the venue. (Instructions below on how to get the interpreter audio)

The Satellite Venue will be located at the "Sanjou Kaikan" on the Hongo Campus of the University of Tokyo, and the networking event will also be held there!

The deadline for purchasing Satellite Venue & Networking Event tickets is April 15th, 2023 10:00 JST!

In addition, we are grateful to have Givery as a "Satellite Sponsor" at the Satellite Venue.

Please stop by their booth when you visit the venue!

Sanjou Kaikan
7-3-1 Hongo, Bunkyo-ku, Tokyo (on the Hongo Campus of the University of Tokyo)

Notes regarding the Satellite Venue

Multi-language support at the Satellite Venue

  • At the Satellite Venue, the talks will be broadcasted in Japanese language.
  • Due to the restriction of the venue and the hybrid nature, we cannot use the usual wireless receiver to pick up the interpreter audio.
  • Please bring a device such as a laptop or a smart phone that can run Zoom, with earbuds to listen the English audio, and chargers for them.
  • Be sure to bring your earbuds/headphones.
  • We will have power strips if you need to charge up for the full day of conferencing. See Electricity in Japan.
  • General announcements at the venue will be done in both English and Japanese.
  • If you need any assistance, please come talk to a staff the reception.

Note: Due to our delay in announcing the broadcasting language, we'll accept cancellation/refund of Satellite Venue ticket via Doorkeeper.

Food at the Satellite Venue

Food is not allowed at the Satellite Venue.

Apparently, a bottled beverage is considered ok.

In other words, there will be no boxed lunch (bento box) this year. Please take lunch at the restaurants nearby.

COVID-19 Measures

At the venue, we generally recommend wearing masks, but we will leave up to the individuals to decide whether to wear a mask or not. For instance, MCs and speakers will likely not wear masks, and generally staff will not force you to wear masks.

We are planning to place hand sanitizers for your use.

We will not be taking your temperatures, but we may not accept you at the venue, if you obviously look feverish. If you are not feeling well, please be considerate to others and stay home.

Ticket Information

Tickets are required for both the "Online Venue" and the "Satellite Venue & Networking Event" (online registration is free of charge). Please register for the tickets from the link below.

About Sessions

Sessions will be held using Discord + Zoom as usual. Even if you have purchased a Satellite Venue Ticket, Day 2 will be held online, so please prepare Zoom and Discord.

Zoom Webinar

Zoom Webinar is an online video chat service provided by Zoom. It will be used to deliver sessions at ScalaMatsuri.

In a webinar, only the speakers and staff can broadcast video and audio. Participants can enjoy the sessions as viewers with their microphones and cameras turned off.

You will need the "Zoom client for meetings" for Windows or Mac.

If you only have a Linux PC, we recommend watching the Zoom Webinar sessions on a tablet or smartphone.

Download Center - Zoom


Discord is an online communication service that has text and voice chat channels in groups called servers. It will be used as the main venue at ScalaMatsuri for session question-and-answer sessions, chats, and socializing.

Your Discord account name (nickname) and icon will be "your face." You may have a chance to chat with acquaintances you haven't seen in a while, which is common at conferences. To make it easier for your acquaintances to find you, we recommend setting your account name or nickname and icon to something you normally use on social media.

When you click on a voice channel in Discord, you will enter the room with your microphone on. You can turn on your camera after entering the room. To prevent howling, please use a headset or earphones. You can listen to the audio through your speakers while muted.

Please post session questions in the #main-track channel on Discord. The bot will automatically translate between Japanese and English, so you can write in either language regardless of the session language.

For comments and chats during the session other than questions, feel free to post them in the #main-track-chat channel. You can enjoy the conference to the fullest by opening both Zoom Webinar and Discord at the same time. You can download the Discord desktop client from the following link:

Download Discord to Talk, Chat, and Hang Out

Open Mic Conference

We will also be holding an "Open Mic Conference" at ScalaMatsuri 2023. This year, it will be held for the first time separately from the main session for both days.

We plan to prepare many 20-minute presentation slots, so please participate and share your ideas! Details will be announced separately on our blog, so please wait for a while.

ScalaMatsuri 2023 Commemorative T-Shirt

The ScalaMatsuri 2023 Commemorative T-Shirt is now available for purchase at the ScalaMatsuri official online shop! Please take this opportunity to get one and come to the satellite venue!

ScalaMatsuri online shop

Inside is an edition of T-shirts called "Ninja sponsor", and if you purchase it, you can become a Ninja sponsor.

As a benefit of becoming a Ninja sponsor, we will grant you a Ninja role on Discord, so please report it to the staff in the dedicated channel on Discord.

*It takes about one week for the T-shirt to arrive, so please hurry if you want to wear it on the day of the event.

"Ninja sponsor" - ScalaMatsuri online shop

We are sponsored by many companies this year as well!

Please check it out!

Sponsors | The largest international Scala conference in Asia

Code of Conduct

ScalaMatsuri Code of Conduct From the Foreword

ScalaMatsuri is dedicated to providing an open conference for all technologists from various regions and communities. We want to make it a fun experience for everyone, inclusive of gender, race, and many different backgrounds whom they may not meet in their daily life.

The following Code of conduct is a guideline to prevent all of us from making inconsiderate behavior, intentional or otherwise. The ScalaMaturi comittee requires all participants, including speakers and sponsors to comply with the Code of conduct as part of our active step to prevent inappropriate behaviors.

The text of our Code of Conduct also provides an overview of the types of harassment that we define; so please take a look at it.

ScalaMatsuri firmly stands against hateful comments against LGBTQ community as harassment, and will issue citations, warnings, and may remove and/or ban participants from the conference at our sole discretion. In the unlikely event that you say something that could be perceived as harassment, we expect you to retract it immediately, regardless of whether or not you are cautioned by staff.

We appreciate everyone's cooperation in ensuring that we have a respectful and enjoyable time with each other.


ScalaMatsuri is a fun and educational event where you can ignite your passion for Scala and contribute to the development of the Scala community.

Make the most of it and deepen your connections with the Scala community, while expanding your knowledge and experience with Scala!

Thank you!