ScalaMatsuri blog

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

ScalaMatsuri 2020 is postponed to October 17-18, 2020

This is a post written by ScalaMatsuri chair Taisuke Oe (@OE_uia), translated by Eugene (@eed3si9n).

Due to the situation of coronavirus disease COVID-19, we are postponing ScalaMatsuri 2020 to October 17th (Saturday) and 18th (Sunday), 2020. I'll go over the details and future outlook in this post.


  • The conference is postponed to October 17th (Saturday) and 18th (Sunday), 2020. Depending on the COVID-19 situation in August, we might to switch this year's edition to an online-only conference.
  • We will accept ticket refund requests until March 31st. Please submit refund request form by March 31st.
  • We are continuing to raise support from personal Ninja Sponsors and corporate sponsorship.


ScalaMatsuri is an annual international conference since 2013 ran by non-profit community organizers as a matsuri (festival) of technologists who love Scala. We consider two major values for hosting ScalaMatsuri.

First is various serendipity at the venue. It provides opportunities for participants to find new technology, new finds through talks and discussions, and meet new people, open source projects, companies, and services.

Second is making chances to distribute knowledge. Speaking at the conference creates an opportunity for the speakers in and out Japan to put their thoughts into a technical presentation (ScalaMatsuri staff provides Japanese subtitles for English slides). This could become a trigger for new technical knowledge to be distributed in the Japanese Scala community, or technical knowledge exchange with the communities overseas.

As a means to efficiently realize those values, we have been renting large event spaces and hosted talks, unconferences, and hackathons as ScalaMatsuri. We think it's essential to provide these spaces for the continual growth of the Scala community worldwide.

However, due to the concern over COVID-19 outbreak, many counties and local governments are requesting to refrain from large-scale events. As a result, companies in and outside of Japan, including our sponsors, are discouraging or prohibiting their employees to attend large gatherings.

Unfortunately expert opinions do not allow for optimism in the trajectory of COVID-19 in May, when we originally scheduled ScalaMatsuri 2020. Even if we could host it in May, we expect many people won't be able to attend, and/or we'd need drastic measures to ensure the safety of participants, which would directly undermine the values we wanted to provide with ScalaMatsuri.

We have considered hosting an online-only conference. We are aware of multiple conferences that have switched to online-only at the last minute and succeeded to some degree. However, given the current ScalaMatsuri resource and our broadcasting knowledge, our call is that two-month preparation might not be enough to host an adequate online conference.

As the result, we determined that the optimum answer for participants, sponsors, speakers, and community would be to postpone ScalaMatsuri 2020 at this point. The postponed dates are October 17th (Saturday) and 18th (Sunday), 2020.

In case the COVID-19 situation does not improve by mid August we are planning to switch this year's edition to an online-only conference. We will prepare for the contingency in parallel. Therefore, we advise participants from overseas not to make travel arrangements until the August announcement.

Minimizing the effect of postponement

ScalaMatsuri is made up of participants, speakers, sponsors, and volunteer staff members who organize the event. We sincerely hope that we can minimize the effect of the conference postponement.

Ticket holders

Some of the ticket holders may not be able to make it to the postponed date. We're sorry that we'll miss you and we would accept refund requests until the end of March, 2020.

If you would like a ticket refund, please submit the refund request form by March 31, 2020. If you can attend on October dates, the ticket will carry through without further actions.

CFP applicants

We apologize for the delay in announcing the speakers. We are determining the acceptance based on the voting results and the recommendations from the selection committee.

We hope to send the acceptance notice in the next 2 weeks. We will confirm with the speaker if they can attend on October 17th and 18th, and will be accepted upon confirmation.

Corporate sponsors

We would like to extend our thanks for supporting ScalaMatsuri.

ScalaMatsuri will provide the same benefits

How to support ScalaMatsuri

We would like to extend our thanks to many who have reached out to support ScalaMatsuri. For individuals, we've created personal Ninja Sponsor; and for corporations we have sponsorships.

Ninja Sponsor

Ninja Sponsor is a sponsorship plan for individuals. You can attend the conference with Ninja Sponsor ticket, and in addition we're planning to create a small token of appreciation for your patronage.

You can apply for Ninja Sponsor from the Doorkeeper page.

It's possible to upgrade a regular ticket to a Ninja Sponsor. In that case, please use the refund request form and cancel the regular ticket.

We also welcome Ninja Sponsor from the speakers.

Corporate sponsorship

If you're interested in corporate sponsorship, please send your inquiry via below form.

ScalaMatsuri inquiry form / 問い合わせフォーム

Future outlook

Even looking back to 8 years of organizing ScalaMatsuri, this is a highly unusual situation that we have never experienced. There remains various uncertainties, and (although we have evaded critical hits) the budgetary burden too is higher than usual.

On the other hand, we stand in a rare situation where we are given extra time to prepare for the conference after the heavy lifting of CFP is over. We hope to use this to improve the conference and to energize the local Scala community.

In particular, in addition to the regular ScalaMatsuri 2020 conference preparation we are planning the following actions:

  • Preparation for online-only conference by October.
  • Planning and organization of a smaller online subevent before October.
  • Call for additional lightning talk speakers.

How to contact us

ScalaMatsuri organizer is available to discuss any questions and concerns by the following contact form.

ScalaMatsuri inquiry form / 問い合わせフォーム


ScalaMatsuri 2020 will be postponed to October 17th (Saturday) and 18th (Sunday), 2020. Depending on the COVID-19 situation in mid August, we might switch to an online-only conference, so we advise participants from overseas not to make travel arrangements yet.

We will accept ticket refunds until the end of March. We hope to send out CFP notices in 2 weeks.

Individual Ninja sponsorship and corporate sponsorship are welcome.

Stay healthy, and thanks for your continued support of ScalaMatsuri!