Open space about functional programming

March 15th. Saturday. 20 geeks. 5 sessions in 1-2 tracks. At Madrid on Rails.

Idea and arrangements

I’m quite interested in functional programming, both theory and practice. The initial idea dates back to 2013, when FP Madrid community was created. I simply wanted to gather during all the day and chatter about FP.

In January 2014 I suggested the idea on a FP Madrid meetup. Initial feedback was encouraging, so I chose a date (March 15th) and a venue (Madrid on Rails). By the way, it is hard to find a venue that is: 1. within Madrid city limits, 2. free, 3. open on Saturdays, 4. and open all day.

A week before the scheduled date I got the final confirmation from Estela from Madrid Emprende. I started up the marketing machine – spamming local communities and dusting off my Twitter account. The company I work for, Osoco, provided us with a delicious breakfast (big thank you!). Friday night before the event there was 35 confirmed attendees.



Finally about 20 fellow programmers made it to the meeting. We started by with the typical introduction about open space principles and rules. After explaining how the schedule was going to be built, there was a round of topic proposals. We filled three tracks, five sessions each. Not a bad result for twenty person group. Though many topics died a natural death due to lack of participants.

Although I facilitated the meeting, I had enough time and energy to attend all sessions of my interest:

  • Intro to Haskell – we went over basic Haskell syntax which I’m still getting used to.

  • Web applications using functional approach – I arrived quite late (we were continuing the Haskell session around the coffee table) and missed the most of discussion. What I proposed was to sketch some Clojure code implementing business logic of some imaginary use cases.

Intro to Haskell

  • Java 8 lambdas – fail; we wanted to do a kata with lambdas. Nobody had JDK8 installed and it was impossible to download it.

  • DDD in Clojure (or in another functional language) – we went through two basic use cases (creation and modification) and wrote some code implementing it with DDD patterns. I felt confused, because I associate DDD with objects having data and behaviour. In Clojure you separate those two into dumb data structures (maps) and functions performing business operations on them (and returning copies of modified data).

  • Category theory – I felt like having a theoretical session about category theory. I struggle to understand it and I wanted to get some tangible examples of categories, arrows and so on. It seemed that everyone was equally confused as me. The conversation shifted to algebraic structures and their counterparts in Haskell. Another question raised was: “do I have to understand all the theory behind functional programming and to be a proficient functional programmer”?

Wrap-up and retrospective

Good open space should close with wrap-up and retrospective. What did we enjoy (or not)? What can be improved in case we, as the community, want to repeat this event?

We did two rounds: personal reflections and a perfection game. Here is the summary of feedback we gathered (I hope I’m not missing any important point):

  • Open the idea marketplace before the event (using a wiki or a more sophisticated tool like Ideascale). It would allow to have more prepared sessions.

  • Not all sessions were run because lack of interest. Voting system with stickers and a reduced number of tracks would have filtered out such sessions.

  • Representations from many communities – FP is a cross cutting paradigm, implemented to lesser or greater extent in a lot of languages. Different backgrounds yield diverse points of view, which enrich discussions.

  • Some more experiences functional programmers expected more engagement from novices (questions, doubts, requests for introductory tutorials). Both parties learn. And this is the purpose of an open space.

  • More facilitation to break the ice at the beginning (I’m the culprit, I was my first facilitation :))

  • Drowsiness after lunch. Maybe we should reduce the duration and finish before (late lunch) – e.g. 9:30 – 14:30 with 4 sessions?

Overall, it was a grateful and enlightening experience for all who sacrificed their Saturday and me as participant and facilitator.

Thanks to