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.


Regal Expressions (lightning talk)

29-02-2020, ClojureD, Berlin


Kaocha, a functional test runner

10-10-2019, Clojure Meetup, Singapore


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


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


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

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.


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


ArrrrCamp: Functional Programming in Ruby

1/2-10-2014, Ghent, Belgium

Frozen Rails: Functional Programming in Ruby

11/12-09-2014, Helsinki, Finland 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. 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.


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.