Writing on software, performance, Open Source and the occasional talk recap.
Latest post
2026-04-12
Most of this blog post was written 8 months ago, between his passing and his funeral. I didn’t find the strength to get back to it for a long, long time, but after talking and reminiscing with a good friend about Piotr I felt it was still worth finishing and publishing. I left most of...
Read post2024-10-16
Finally I did it - I spoke at CodeBEAM EU - not only that, it was a keynote! Which is a bit scary when the likes...
Read more2024-05-06
This is just a quick remark that I’m on a podcast again! It’s programmier.bar and I’m talking with the hosts about Ruby & Rails!
Read more2024-05-01
No, I’ve not gone to the click-baiters (“10 tips that will change your life today!!!”), but I chose to limit myself to just 10 so that...
Read more2024-03-21
Welcome to the last part of the interview series! In this part we’ll take a look at more general interviews – usually they cover a variety...
Read more2024-02-14
And somewhat belatedly the slides I presented at the Ruby User Group Berlin February meetup almost 2 weeks ago 😅 I’ve been extremely busy, so sorry...
Read more2024-02-13
Back last year in June 2023 I was lucky to speak at lambda days 2023 about one of my favorite topics: Open Source! And it’s not...
Read more2024-01-08
I’ve wanted to revisit “Tail Call Optimization in Elixir & Erlang – not as efficient and important as you probably think” (2016) for a while -...
Read more2023-12-22
As per usual you can check out the official Changelog for what exactly happened. This is a more personal look, featuring both the highlights of the...
Read more2023-12-18
In Elixir and on the BEAM (Erlang Virtual Machine) in general we love our processes - lightweight, easily run millions of them, easy lock-less parallelism -...
Read more2023-12-14
Not too fun news here but huge thanks to Jean Klingler for reporting it.
Read more2023-11-29
After making it through the initial application selection and conquering a first set of introductory interviews the interview process often moves on to some form of...
Read more2023-11-28
Last week I found myself at my old RailsGirls/code curious project group the rubycorns coaching a beginner through the FizzBuzz coding challenge. It was a lot...
Read more2023-11-09
Not really a big blog post this time around but benchee 1.2.0 was just published to hex.pm.
Read more2023-11-07
Applying at and interviewing for a company is potentially one of the most valuable skills one can have - it’s not important for the job, but...
Read more2023-10-23
Back last year in June of 2022 I gave what’s one of my favorite talks (of myself) at the wonderful conference Code Beam A Coruña. It’s...
Read more2022-03-08
Benchee 1.1.0 has finally hit hex.pm. After, well, almost 3 years. So, in this blog post we’ll dive into:
Read more2022-03-08
Sorry y’all, for the silence between.
Read more2020-08-24
It has been far too long, more than 3.5 years since the last edition of this benchmark. Well what to say? I almost had a new...
Read more2020-03-06
Yesterday at RUG::B I tried something I’d never done before: a more personal, story driven talk. And in order to adequately illustrate it and how different...
Read more2019-11-10
I had the great pleasure to finally speak at Øredev! I wanted to speak there for so long, not only because it’s a great conference but...
Read more2019-10-10
Back in July I had a great time at Heart of Clojure - the first conference who finally allowed me to share my thoughts on the...
Read more2019-09-04
At the end of a lengthy job search I decided to become a freelancer helping companies onboard onto Elixir, helping them with their development projects and...
Read more2019-07-09
NO LONGER (REALLY) LOOKING FOR A JOB
Read more2019-07-05
I just released statistex - a library to calculate statistics based on a given data sample. It’s an extraction from my benchmarking library benchee and part...
Read more2019-07-05
In a trial run for Heart of Clojure I gave my talk Functioning Among Humans yesterday at RUG::B. It covers topics very close to my heart...
Read more2019-06-24
I always loved the idea of Property Based Testing, it was the most mind blowing idea I encountered while learning clojure many years back. However, I...
Read more2019-06-17
Ever wanted to implement something board game like in Elixir? Chess? Go? Islands? Well, then you’re gonna need a board! But what data structure would be...
Read more2019-04-24
The thought that people seem to think of GenServers and supervision trees in the elixir/erlang world as too essential deterring people from using these languages has...
Read more2019-04-08
All the way back in June 2016 I wrote a well received blog post about tail call optimization in Elixir and Erlang. It was probably the...
Read more2019-03-28
It’s finally here - benchee 1.0! 🎉🎉🎉 The first benchee release was almost 3 years ago - it started a mission to improve benchmarking tooling in...
Read more2019-03-05
I had a wonderful time at Ruby On Ice! I gave a talk, that I loved to prepare to formulate the ideas the right way. You’ll...
Read more2019-02-11
Long time since the last benchee release, heh? Well, this one really packs a punch to compensate! It brings you a higher precision while measuring run...
Read more2018-04-17
I was supposed to give this talk at ElixirConf.Eu, but sadly fell ill. These are the slides (still titled alpha-1) that I used to give it...
Read more2018-04-01
edit: This was an April’s fools joke. However, bunny will remain functional. It’s only implemented as a thing wrapper around benchee so unless we completely break...
Read more2018-03-27
I managed to get into Lambda days this year and got a chance to present my benchmarking talk. You can watch the video here and check...
Read more2018-03-26
I wrote a nice blog post for the company I’m working at (Liefery) called “The curious case of the query that gets slower the fewer elements...
Read more2018-01-27
I gave my first ever keynote yesterday at Ruby on Ice, which was a lot of fun. A lot of the talk is based on my...
Read more2017-12-12
Lately I acquired a new hobby. I went around and asked experience Rails developers, whom I respect and value a lot, how many users the following...
Read more2017-11-14
Most people are either firmly on the “Yes!” or the “No!” side when it comes to discussing comments and their status as a code smell. But,...
Read more2017-10-25
It’s been a little time since the last benchee release, have we been lazy? Au contraire mes ami! We’ve been hard at work, greatly improving the...
Read more2017-08-29
Have you seen the MJIT benchmark results? Amazing, aren’t they? MJIT basically blows the other implementations out of the water! What were they doing all these...
Read more2017-07-26
People like to argue about programming languages: “This one is better!” “No this one!”. In these discussion, often the performance card is pulled. This language is...
Read more2017-07-10
When I was at the excellent Pivorak meetup I had the chance to give an “inspirtational” lightning talk. So I took this chance and prepared...
Read more2017-07-09
Hello from the amazing Polyconf! I just gave my Stop Guessing and Start Measuring talk and if you are thinking “why do you post the slides...
Read more2017-06-19
My slides & video from visiting the excellent WRUG (Warsaw Ruby Users Group). The talk is a variation of the similarly named elixir talk, but it...
Read more2017-06-19
The following is the first part of my visit to Warsaw in April (sorry for the super late post!). As part of the visit, I also...
Read more2017-01-24
A little more than a year ago I published a blog post benchmarking different ruby implementations against a bot that plays Go which I wrote. Now...
Read more2016-12-06
In software development, and many other disciplines, people strive for mastery - you want to get better to be great something. For some reason failure is...
Read more2016-12-03
I’m at Elixirlive in Warsaw right now and just gave a talk. This talk is about benchmarking - the greater concepts but concrete examples are in...
Read more2016-12-01
The last days I’ve been hard at work to polish up and finish releases of benchee (0.6.0 - Changelog), benchee_csv (0.5.0 - Changelog) as well as...
Read more2016-11-24
And here goes the video from Rubyconf Portugal - which was a blast! This talk mainly focuses on the latter explicit part of the title and...
Read more2016-11-10
As you might have seen on this blog or on twitter I’m thoroughly enjoying elixir. One thing that I found to be thoroughly missing is deep_merge...
Read more2016-10-28
A small lightning talk I gave at Rubyconf Portugal that is complementary to my “elixir & phoenix - fast, concurrent and explicit” talk in that it...
Read more2016-10-27
And here go the slides for my elixir and phoenix talk focusing on the great features that both bring to the table and make your development...
Read more2016-10-27
A talk about AlphGo and techniques it used with no prior knowledge required. Second talk of the Codemotion Berlin series, mostly the same talk I gave...
Read more2016-10-25
This is a remix and extended version (40 minutes) of the elixir and Phoenix talk I gave in the beginning of the year at the Ruby...
Read more2016-10-13
Another month and another release of my Elixir (micro-) benchmarking library benchee. This particular release focusses on unit scaling. E.g. instead of displaying that you had...
Read more2016-09-15
The publishing/video partner of Full Stack Fest was amazingly fast in publishing the video. Kudos to them! So after publishing the slides here goes the video!...
Read more2016-09-12
Today I made a little 0.4.0 release of my elixir benchmarking library benchee. As always the Changelog has all the details. This release mainly focusses on...
Read more2016-09-06
I gave this talk at Full Stack Fest (achievement unlocked!) and I practised it before at Strange Group. It’s designed to not really require any previous...
Read more2016-07-12
Yesterday I released benchee 0.3.0! Benchee is a tool for (micro) benchmarking in elixir focussing on being simple, extensible and to provide you with good statistics....
Read more2016-06-16
(Automatic) Tail Call Optimization (TCO) is that great feature of Elixir and Erlang that everyone tells you about. It’s super fast, super cool and you should...
Read more2016-06-13
Less than a week after the initial release of my benchmarking library Benchee there is a new version - 0.2.0! The details are in the Changelog....
Read more2016-06-07
If you look around this blog it becomes pretty clear that I really love (micro) benchmarking. Naturally, while working more and more with Elixir (and loving...
Read more2016-06-02
The upcoming elixir 1.3, available as a release candidate, brings along many cool new features such as Calendar Types and (finally!) test groups for ExUnit. My...
Read more2016-05-27
This is a talk I gave at the Polygot Tech Meetup in Berlin in April. It has parts of my previous elixir talk while adding a...
Read more2016-05-27
This is the first talk I ever gave about my two new favorite technologies to play with (at home and at work) - Elixir and Phoenix....
Read more2016-04-12
As I just happened upon it again, I gotta take a moment to talk about one my most despised ruby code patterns: Struct.new(...).new - ever since...
Read more2016-04-06
So far in this post series I covered what you should be aware of before you start organizing a meetup and the 5 basics defining your...
Read more2016-04-04
After looking at some things you should be aware of before you start your own meetup. Let’s take the next step and ask: “What will your...
Read more2016-03-31
I’ve been running theRuby User Group Berlin for over 3 years now. Additionally, I’ve been running the React.js Berlin meetup for about a year now. These...
Read more2015-11-30
The world of Artificial Intelligences is often full of performance questions. How fast can I compute a value? How far can I look ahead in a...
Read more2015-11-21
I was happy enough to present at rubyconf this year. Here go my video, slides and abstract!
Read more2015-11-04
Yesterday I gave a talk at Codemotion Berlin, it was “Optimizing For Readability” - an updated version of my “Code is read many more times than...
Read more2015-10-20
There are a couple of mantras that exist across programming communities, one of them is to avoid duplication or to keep it DRY. Programming languages equip...
Read more2015-07-18
I gave a rather spontaneous talk at the July edition of the Ruby User Group Berlin (which I organize). One of the speakers cancelled so I...
Read more2015-07-11
I wrote a blog post about my favorite Ruby implementation JRuby over in the eurucamp blog. It’s an article introducing people to JRuby highlighting the benefits...
Read more2014-12-09
Can you still remember the first program you ever wrote? The first program you ever wrote in your current favorite language? How far you’ve come and...
Read more2014-11-19
Ruby is well known for being a good language to build Domain Specific Languages (DSLs). Want to take a look at an example? Sinatra is a...
Read more2014-11-18
Hello everyone - it’s finally that time. After finishing my Master’s and a bit of a break I’m finally looking for a job. For the impatient,...
Read more2014-11-14
I started reading Functional Programming Patterns in Scala and Clojure - a nice book so far. However, right at the beginning in Chapter 1.1 “What is...
Read more2014-11-03
Talking to developers and reading about open source I often get the feeling that the general notion is that open source is just about code and...
Read more2014-07-28
Finally the video of my talk at JRubyConf 2013 in Berlin is online. It was my first full length talk at a conference, I gave it...
Read more2014-05-26
As you might have noticed a big project I’ve been working on for almost 2 years got its first release on the 10th of May a...
Read more2014-04-16
With HTML5 video and audio tags are here and ready for use to easily enhance your websites with audio and video. The tags are available in...
Read more2014-02-24
With a bit too much of delay, here are the slides from the 15 minute “Code is read many more times than written” talk I gave...
Read more2014-01-19
I just released version 0.3.0 of my little aspect oriented programming/adding callbacks to methods library after_do! You can find an introduction here. So what is in...
Read more2014-01-13
I often see people who really want to contribute to open source projects. And that’s great! But often it’s not easy to get started. “What project...
Read more2013-12-19
I want to introduce you to a little gem I built and use in some of my projects: after_do. What it does is pretty simple: you...
Read more2013-10-23
Hi everyone, today was a great day! Today was the first day of the second edition of the course about the basics of web development I’m...
Read more2013-10-07
So if you are here, you are probably looking for some Ruby/Rails engineers. Many companies (and therefore recruiters) are but they are hard to find. Luckily...
Read more2013-09-06
Hi everyone, yesterday I gave a presentation at the Ruby User Group Berlin about some of my favorite coding practices. Those are general and not particular...
Read more2013-08-15
So with my last presentation given in a not really mature presentation tool I still wanted to provide PDF slides for people to look at. So...
Read more2013-08-14
So today i gave my first full time presentation at a conference - JRubyConf that is. It went well! Thanks for having me! :-) My presentation...
Read more2013-07-18
An introduction about JavaScript web workers I gave at Berlin.js on the 18th of July 2013. It introduces the concept of web workers for simple parallel...
Read more2013-07-17
My Google Summer of Code has been going on for one month now. The first commit on the shoes4 repository is almost one year and two...
Read more2013-06-14
A Rails Girls workshop (Photo credit: Kerstin Kollmann (CC) NC-ND-BY) There are many great movements out there teaching people how to code: Rails Girls and RailsBridge...
Read more2013-05-27
Hi everyone, this is just a quick note that I’m accepted as a student of Google Summer of Code. I will be working on Shoes, more...
Read more2013-05-04
Hi everyone, It’s the well known web application introduction, this time without the Ruby introduction as the Ruby Monsters already did this! This time it also...
Read more2013-04-24
Hi everyone, during the last week I spent a large amount of time creating a Cheat Sheet for Rails beginners! So, here it is: http://pragtob.github.io/rails-beginner-cheatsheet/ I...
Read more2013-03-03
So I just gave a lightning talk about shoes. Here are the slides for talk, it was (mostly) a stripped down version of an introduction talk...
Read more2013-02-27
Hello everyone, just a quick note but I’m extremely excited to finally announce that I will be teaching a course about the basics of web development...
Read more2013-02-23
Hi there, So here are the slides from my talks from the Rails Girls Berlin workshop on Saturday, in their chronological order: Introduction to web applications...
Read more2012-12-12
Hello everyone, for my talk on Saturday I prepared cookies. Apparently people really liked them (yay!) and I got quite some requests for the recipe. It’s...
Read more2012-12-08
Hi everyone, here go the slides from my talk this morning at the RailsGirls Berlin December workshop. It’s a basic introduction to web applications and Ruby....
Read more2012-11-27
Hi everyone, at first sorry to my English readers but the remainder of this post will be written in German! This is due to the fact...
Read more2012-10-22
Here are the slides from the lightning talk I gave at a RailsGirls Berlin event on Saturday. It’s basically a lightning talk version of my blog...
Read more2012-10-19
I often have the feeling that programming and software development is largely misunderstood. Many people seem to still have ancient believes about how software development works....
Read more2012-10-09
I was at an event two days ago where the topic was teaching programming. During this event attendees raised the problem, that there aren’t enough software...
Read more2012-09-25
After upgrading my PCs to Linux Mint Debian Edition, and thereby using the Cinnamon user interfacen, I encountered a particularly bothersome behaviour: For every incoming Skype...
Read more2012-09-14
So my PC has 2 wireless adapters. One crappy internal one and a good external one which I bought because the internal one is so bad....
Read more2012-09-12
So every once upon a time I run into the situation, that I have a newly set up machine and have to configure my system again...
Read more2012-08-17
Hi everyone, I just slightly updated my slides Slides: Where to go from here (PDF) for the RailsGirls workshop today. You can also watch them and...
Read more2012-08-14
Hi everyone, just a quick note I updated my beloved Resource section with some quite nice new resources. I also restructured it so that Ruby and...
Read more2012-08-13
This is just a little post recapping some of my experiences from the last RailsGirls Berlin workshop. By the way, we’ve got a new workshop upcoming...
Read more2012-07-27
My good friend Tobias Metzke and I worked on extending the Cloud9 IDE with some tool support for CoffeeScript and Jasmine. This was done during a...
Read more2012-07-14
Hi everyone, I just gave a lightning talk at RailsGirls Berlin about places where you can continue to learn about Ruby and Programming - especially for...
Read more2012-07-06
Hi everyone, I gave a talk about the Shoes GUI toolkit/DSL (depending on your point of view) at the Ruby User Group Berlin yesterday and I...
Read more2012-06-14
This post introduces a technique, which we have labeled “3D Planning Poker”. It is aimed at helping agile teams with their user story estimations. It was...
Read more2012-06-03
CoffeeScriptis a nice layer on top of JavaScript that takes away quite many of JavaScripts quirks and rough edges. I really like it as it makes...
Read more2012-06-02
I’ve been at the XP 2012 conference and I had a great time and a lot of interesting conversations. One topic that particularly intrigued me is...
Read more2012-05-13
Some weeks ago I installed Linux Mint Debian edition after being a loyal and happy user of the Linux Mint main edition for some years. It...
Read more2012-04-18
Hello everyone, I’m responsible for the student volunteers of the XP 2012 conference in Malmö, Sweden. The XP 2012 is a big international conference about agile...
Read more2012-04-17
A few days ago I finally made the step to switch from Linux Mint main edition (Linux Mint 10 was getting old) to the all new...
Read more2012-03-06
It is time to secure your Rails apps! I mean it is always time to do that, but (as you might have heard) github just got...
Read more2012-03-02
You probably know that there is the Waterfall process - by now feared by most as “the father of the plan driven approach”. Some may even...
Read more2012-02-01
TravisCI is an awesome free continuous integration system that just takes your github repositories and then runs all your tests - it is pure awesomeness and...
Read more2012-01-15
Do you know what #rubythankful is? It’s a hash tag, those are commonly used on Twitter to mark special things. There is even a website displaying...
Read more2011-12-22
Before we get to the real topic and the source of some quite big headaches for me, I want to explain something first.
Read more2011-12-18
Problem
Read more2011-12-13
I just spent the weekend in Hamburg at a ThoughtWorks boot camp. So this blog post is for people who want to know what a boot...
Read more2011-10-15
“Pragmatic Thinking & Learning” is a book full of knowledge, and that is also what it is about: knowledge. More precisely it is about your knowledge,...
Read more2011-10-02
So some weeks ago (unfortunately I didn’t really have the time to post this immediately) I ran into the following problem, I wanted to match the...
Read more2011-10-01
In my course Global Software Engineering, I wrote a paper about the topic whether a distributed project can be agile. It’s just a 3 pages essay...
Read more2011-09-13
Yesterday I ran into a nasty problem while doing a task for Mendicant University (it is an awesome free university for learning Ruby and other stuff)....
Read more2011-09-09
OAuth is a protocol used to authenticate an application in order to use the API of a service. Here we’ll use Twitter as an example. The...
Read more2011-09-09
As I just stumbled upon this and I need this: So how do you use ruby gems with shoes? Shoes is kind of a ruby interpreter...
Read more2011-09-07
Just a quick solution so I don’t (and everybody else as well) doesn’t lose those valuable links just given to me by Steve Klabnik. So how...
Read more2011-08-30
Hey folks, just a quick post: I just created a page containing many of the resources I stumbled upon while learning about programming, software engineering, web...
Read more2011-08-29
“The Agile Samurai” is an awesome book about agile software development by Jonathan Rasmusson. I read it this march so my memory isn’t the freshest but...
Read more2011-08-20
So what are blogs about? From my current point of view they are about sharing knowledge and ideas with other people. And of course to discuss...
Read more2011-08-13
So a while back while reading “The Pragmatic Programmer” the idea of keeping track of solutions was introduced. So that you don’t have to find a...
Read more