Public Speaking
Tech talks (full-length and lightning talks) I’ve given in public, in reverse chronological order.
If you’re not sure how to make the slides work, try hitting the space bar.
2026
Datastar & Clojure
2026-10-16, Stockholm Clojure Café
2020-2025
Please bear with me while I backfill these entries. You can find most of my slides in my conf-talks repository
2026-sound
Dutch Clojure Days, a talk about Sound theory and Music, demonstrated with Overtone.
2026-licli
An online talk for Nubank’s Clojure Guild about lambdaisland/cli
2026-bbconf
A lightning talk at Babashka Conf Amsterdam about lambdaisland/cli
2025-gaiwan-stack
An online talk for London Clojurians about the Gaiwan/Lambdaisland stack.
2024-conj-overtone
A lightning talk of Overtone at the Clojure/Conj
2024-hoc-intro
My introduction slides for the opening of Heart of Clojure 2024
2023-bi-and-reporting
A talk at the Clojure/conj about analytics and BI on top of Datomic, using Plenish.
2020
2020-data-driven-with-malli
An online talk about driving various parts of an application through Malli schemas.
Regal Expressions (lightning talk)
29-02-2020, ClojureD, Berlin
2019
Kaocha, a functional test runner
10-10-2019, Clojure Meetup, Singapore
2018
Clojure REPLs, closing the loop
25-02-2018, Clojure meetup, Taipei
The Art of Tree Shaping with Zippers
18-10-2018, Clojure Meetup, Denver, Colorado
2017
Clojure vs Emacs Lisp
13-04-2017, Clojure meetup, Berlin
29-03-2017, Emacs meetup, Berlin
ClojureScript and React
20-03-2017, Berlin
Presented at the Berlin React.js meetup
Emacs and Clojure, a Lispy <3 Affair
22-02-2017, Berlin
Presented at the Emacs Berlin user group
2016
Why React and re-frame are fast: 7 performance hacks
11-10-2016, Berlin
Did this talk at the Clojure meetup in Berlin.
Treating Markdown As org-mode
29-09-2016, Berlin
A lightning talk for Emacs Berlin
Introducing core.spec
30-06-2016, Poznan, Poland 10-09-2016, Tampere, Finland
I gave an early version of this talk for the Clojure meetup in Berlin, and then a more polished version for a broader audience at Polyconf 2016. Finally I did a version adapted for a Clojure programmer audience at ClojuTRE.
Burn Your Idiomatic Ruby
An exploration of the concept of idiomatic code, what it means, and what it implies.
07-01-2016, Berlin, Germany
A try-out at Rug::B in preparation of RubyConf Australia
10/11/12-02-2016, Gold Coast, Australia
19-04-2016, Brussels, Belgium
Clojure Berlin: A Demo of the New Chestnut
13-01-2016, Berlin, Germany
A demonstration of the new version of Chestnut.
Rug-B: Burn Your Idiomatic Ruby
07-01-2016, Berlin, Germany
An exploration of the concept of idiomatic code, what it means, and what it implies. This was a showcase for RubyConf Australia.
2015
Rug-B: Growing a LISP
04-06-2015, Berlin, Germany
The idea for this talk had been floating in my mind for a little while, and when another speaker canceled it seemed the perfect opportunity to try it out.
In the spirit of Guy Steele’s Growing a Language, I “grow” a LISP by step by step defining concepts, starting from the absolute basics. The talk has a bit of a performance vibe to it, with minimal slides and a particular rhythm. Something I might push a bit more in future versions :)
ROSS Conf Vienna, Yaks
26-04-2015, Vienna, Austria
A conference-slash-hackaton where I presented Yaks, and then worked with a small group of people on several features.
RubyConf Lithuania / RubyConf Belarus, 22 March, Hypermedia in Practice
21-03-2015, Vilnius, Lithuania / 22-03-2015 Minsk, Belarus
A mirror event, I did the same talk at both places
I also did a lightning talk in Belarus about Slippery, the tool I built and use to make slides.
RubyFuza: Hypermedia, a Success Story (lightning talk)
5/6-02-2015, Cape Town, South Africa
I did this talk in Emacs. It’s mostly images and code examples. The source files are here
2014
ArrrrCamp: Functional Programming in Ruby
1/2-10-2014, Ghent, Belgium
Frozen Rails: Functional Programming in Ruby
11/12-09-2014, Helsinki, Finland
Lightning.io: How to Draw an Owl With Overtone
16-08-2014, Świnoujście, Poland
A live demo making music with Clojure and Overtone.
Rug-B: Building Hypermedia APIs with Yaks
03-07-2014, Berlin, Germany
An introduction to REST and Hypermedia, followed by a demonstration of Yaks.
RubyConf Taiwan: Functional Programming in Ruby
25-04-2014 - 26-04-204, Taipei, Taiwan
My first chance to do a full length talk on this exciting topic:
And a lightning talk on using Ruby for learning Chinese.
Wroc_love.rb: Nobody Knows Ruby
14-03-2014 - 16-03-2014, Wrocław, Poland
Showing off in 5 minutes some lesser known Ruby features. Both highly useful (extended regular expressions) and highly comical (flip-flops).
Rug-B: Slippery Slides
08-03-2014, Berlin, Germany
Lightning talk about the slippery gem. A highly hackable tool for building in-browser slide decks based on Markdown.
Kod.io: Web Services, past, present, future
01-03-2014, Linz, Austria
A talk about the web, REST, hypermedia, the past, the present, and the future.
Rails Girls Brussels: Learning To Learn
08-02-2014, Brussels, Belgium
A short talks that tries to inspire and give some practical tips for beginners.
2013
RubyConf Argentina: Web Linguistics
27-11-2013 - 28-11-2013, Buenos Aires, Argentina
Final version of this talk about formal languages, security, and the perils of using strings plus manual escaping.
This is the most conceptual, high level version of this talk I’ve given. It was also the first time I drew all my slides in Inkscape.
I also did a lightning talk on functional programming in Ruby, this time live coding with some Emacs macros to guide me.
Rug-B: Functional Programming Demystified, with Ryan Levick
07-11-2013, Berlin, Germany
A joint talk where Ryan explains the theory, and I show how that works in Ruby.
ArrrrCamp: Functional Patterns for Ruby
03-10-2013 - 04-10-203, Ghent, Belgium
Adaptation of the lightning talk I did at JRubyConf. People really liked it, which sparked me to start writing a book on the subject, The Happy Lambda.
eurucamp: Web Linguistics
16-08-2013 - 18-08-2013, Berlin, Germany
A rewrite of the talk I did at Rulu, trying to make it more concrete and entertaining.
I also did a talk at the Rails Girls workshop, titled “Learning to Learn”
JRubyConf.EU: Functional Patterns for Ruby
14-08-2013 - 15-08-2013, Berlin, Germany
A spur of the moment lightning talk, showing some “programming in the small” patterns that I had stumbled upon while working on Hexp, which heavily uses immutability.
Rulu: Web Linguistics
20-06-2013 - 21-06-2013, Lyon, France
First iteration of my “Web Linguistics” talk, which diggs into the combination of formal languages and security. It is a call to stop using strings for structured data, especially data that complies to a formal language, and use data structures, i.e. syntax trees instead.
Of the different versions of this talk this one is the most theoretical.
Wroc_love.rb: Security
01-03-2013 - 03-03-2013, Wrocław, Poland
A lightning talk summary of “YAML is the new eval” video and taking part in the security panel video.
Rug-B: YAML is the new eval
09-02-2013, Berlin Ruby User Group, Germany
Security as an emergent property, and an in depth look into the security issues Rails had had the past months.