ScalaMatsuri blog

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

About open mic conference

Hello. This is Ikeda from ScalaMatsuri organizer.

Scala Matsuri 2022 is coming up soon!

Now that the program for Day 1 has been released I hope you are looking forward to the conference, but we haven't had chance to introduce you to the open mic conference on Day 2.


In this post, I would like like to go over the following: - What is an "open mic conference" on Day 2? - What kind of sessions are the ScalaMatsuri attendees interested?

About open mic conference

In short, an open mic conference the same as what we have been doing as an unconference.

Unconference: A style of conference in which the lecture contents or the speakers are not determined until the day of the conference, and the participants create their own conference by giving a talk on their own. Often the attendees who are interested in giving a talk proposes them during the conference, and the program is determined by the ballot of other attendees.

We wanted to use a more familiar name than "unconference", so we are going with "open mic conference." open mic is defined as:

a session in a club during which anyone is welcome to sing or perform stand-up comedy.

We think this analogy works for the open conference as well.

Open mic conference proceedings

The details of open mic conference is described in the website as well

but we've created a GitHub repo to collect session and LT (lightning talk) ideas.

Please submit the idea you would like to facilitate to GitHub issue.

You can start submitting now. When you find an idea that you'd like to attend, please vote using GitHub reactiion. We will conduct "morning session" on the open mic conference day (2022-03-20 10:00 JST), and we will create the program together based on the collected ideas and your voting results.

Time Duration Zoom A Zoom B
10:00 ~ 60min Morning Session
11:00 ~ 15min Break
11:15 ~ 30min Session A Session B
11:45 ~ 30min Session A Session B
12:15 ~ 45min Lunch Break Lunch Break
13:00 ~ 15min Break
13:15 ~ 15min LT1 - A LT1 - B
13:30 ~ 15min LT2 - A LT2 - B
13:45 ~ 15min Break
14:00 ~ 30min Session A Session B
14:30 ~ 30min Session A Session B
15:00 ~ 15min Break
15:15 ~ 30min Session A Session B
15:45 ~ 30min Session A Session B
16:15 ~ 15min Break
16:30 ~ 15min LT3 - A LT3 - B
16:45 ~ 15min LT4 - A LT4 - B

There two types of sessions based on the length: LT (lightning talk, 15min), and 30 min sessions. We have created two kinds to accommodate varying size of the talks. (Note: LT doesn't necessarily take up the entire 15min)

In addition to the normal tracks there will be virtual booths by the sponsors. Please take a look at the schedule to check out some of the contents available during the break time.

Previous program

The following is an excerpt from the Day 2 of the previous conferene:

10/18 ScalaMatsuri 2020 Unconference Timetable · GitHub


  • How is everyone doing with Scala training? Case studies
  • The ultimate Scala in practice: Live coding with Airframe on Scala + Scala.js
  • Rough explanation of a CQRS/Event Sourcing system built with akka-typed
  • Show us your Scalafix rules at work!
  • Horrible Scala Code Championship

These sessions encompassed from round table, tutorial, knowledge sharing, and fun events like 'Horrible Scala Code Championship.'

If you have a prepared talk that's fine, but we welcome half-baked "I can talk about X" or ideas.

If you're interested in facilitating a session or have a talk you would like to give, please submit an issue.

Categories ScalaMatsuri attendees are interested in

We have taken a survey of categories of talks the attendees are interested in, so maybe you could use it as a reference in coming up with ideas for the open mic conference.

The following tally covers 212 respondents who agreed to have their response reused:



  • General functional programming or category theory(45 votes)
  • Software design and architecture(38 votes)
  • Scala3(30 votes)
  • Case studies(19 votes)
  • Effect System (Cats Effect / Monix / ZIO / eff etc.)(19 votes)
  • Big Data / Fast Data / Data Science(17 votes)
  • Intro to Scala(13 votes)
  • DevOps & Tools(7 votes)
  • Organization related (6 votes)
  • Inspirational / Uplifting(1 votes)

As we can see, looks like functional programming (category theory and effect systems), software design and architecture, and Scala 3 seems to be the most popular topics.

In closing

We are approaching ScalaMatsuri, but open mic conference lets you participate at last minute. If you've been interested in giving a talk, please submit an issue at Issue.