Recently, I had a chance to participate in organisation of Poznań’s part of Global Day of Code Retreat. Poznań JUG together with Poznań GTUG (which stands from Google Technology User Group) have organised 2nd Code Retreat in Poznań. Just to remind you, first one was held in January 2011 and resulted (apart from loads of great code) with this awesome movie (thanks to Zbigniew Wantuch).

But let’s get to the merit, our event was a part of Global Day of Code Retreat (GDCR). The idea is simple, on 3rd of December developers from all around the world joins their local Code Retreats to experiment and improve skills in the area of Test Driven Development, Pair programming and clean object design. Gathering 2000 developers and forcing them to deal with Conway’s Game of Life itself is awesome, but it seems that apart from that, Corey Haines (and others) managed to create a real, interesting community around the idea of Code Retreat – which is ultimately awesome ;-).

Thanks to courtesy of Poznań University of Technology we had a really nice venue for our Code Retreat. Initially I was hoping to get more than 40 but finally we had 35 registered participants, 20 of them managed to get to the event. What’s interesting, only three or four people were attending our first CR.

Most of people who came to CR were familiar with coding in Java, but there were also a few working in Javascript and Ruby. In an announcement I wrote that knowledge about programming in Java is obligatory (as a common denominator) but pairs can work in whatever language they want. It seems that this requirement is not necessary, because mixed-language pairs had a lot of fun.

As for knowledge about TDD and experience in pair programming, most of participants knew that these techniques exist but did not have a chance to practise them in the past. So, during the first two session (and retrospectives) our great facilitators Wojtek Buras (from PSI Polska), Jakub Milkiewicz (from Poznań JUG) and Paweł Stawicki (from Software Mill) had quite a lot to do.

We had 5 sessions:

• session #1 – No constraints
• session #2 – Develop a solution to the problem with the constraint that no computers are to be used in the first 10 minutes
• session #3 – Develop a solution in which no primitives can be used – the solution must be built on classes;
• session #4 – TDD as you meant it
• session #5 – No touchpad/mouse, small methods (<5 lines)

During session everything went very smooth (at least IMHO). Apart from great coding session we had really cool retrospectives (people didn’t have any problems to speak about their problems and discuss).

When we will organise CR next time we will surely add one more session (maybe even two). I have also my personal wish list of constraints ;-):

• while reading notes from hosts of other CR I saw that silent session (or Mute Evil Pair) was really funny one. In this exercise developers are not allowed to speak, they can only communicate through code.
• Another interesting idea is legacy code session. After the previous session ends no one is allowed to delete code (!), instead of swapping pairs, people swap their workstations.
• No loops/no conditionals because this sounds like a real challenge 😉

Considering that everyone is asking when we will have next CR it seems that we had really successful workshop ;-). Pictures from CR are available here.

Big thanks to Łukasz Stachowiak and Daniel Mendalka for their organisational effort – thanks guys!