Coderetreat is a one day intense workshop for software developers for imporving their development skills by practicing. This is the material I presented at the beginning of coderetreat I facilitated on May 2014.

1. Code Retreat
Lemi Orhan Ergin
Agile Software Craftsman
practice to master your crafts

2. Agile Software Craftsman
Passionate Developer and Coach
Sony & GittiGidiyor/eBay
LEMİ ORHAN ERGİN
@lemiorhan
lemiorhanergin.com
@lemiorhan

3. like to work alone
feel safe to work on confort zone
have to focus on daily work
skip writing tests
cannot find time to experiment
not willing to learn new practices
do not think about design
focus on gettings things done
over-engineer
do not refactor
Developers

4. have to improve their craft
Developers

5. is the best way how we improve our craft
Practicing

6. How to Practice
Challenge
Repeat
Feedback
again and again and again and again

7. How to Practice
No Pressure
do not complete the task
but master it

8. practicing
!
mastering
Code Retreat is about
and

9. writing
the perfect code
Code Retreat is about

10. learning through pairing
extending your confort zone
no pressure of daily work
experimenting
learning new practices
thinking deeply about design
building structures simple
developing whenever required
refactoring
Code Retreat is about

11. 1 day coding
45 minutes sessions
Pair programming
Test first development
Different partners on each session
Different constraints
Format

12. Schedule
Retrospective
Break
Closing
Ceramony
Coding 45
10
5 5 5 5 5
10 10 10 10
15
45 45 45 45 45
Lunch

13. History
The idea was spawned at
CodeMash Conference’09
!
The owners of the idea
Gary Bernhardt
Patrick Welsh
Nayan Hajratwala
Corey Haines
!
First was held on
January 24, 2009
Corey Haines
https://www.flickr.com/photos/charliekilo/7717370426

14. Global Day of
Code Retreat
2000+ developers
150+ locations
20 timezones
16 hours of coding
6 continents
coderetreat.org
Coderetreat Community Network
14th of December
https://www.flickr.com/photos/stef3d/4560661663

15. Code generation is not important
Generate code by thinking the design
Focus on naming test cases
Focus on Red/Green/Refactor cycle
Why Repeating?

16. You are not your code
Learn to go slower
Focus on being better
Do not think about finishing
It’s all about practicing
Why Deleting?

17. Language agnostic
Do not try to complete
Focus on practicing
Write code than open to accept change
Follow 4 rules of simple design
Delete code after each session
Have fun
Principles

18. SOLID Principles
Law of Demeter
Design Patterns
4 Rules of Simple Design
Design
Guidelines

19. Simple Design
Simple design in one that is
easy to change.
We don’t know exactly what is going to need to change
We’ll never be more ignorant than we are at this moment

20. Simple Design
Tests pass
4 Rules of
“Tests pass” can be a significant factor in
making changes. If you have to ask how fast
your test suite should be, it should be faster
1

21. Simple Design
Express Intent
4 Rules of
Paying attention to the names and how your
code expresses itself is the key.
2

22. Simple Design
No Duplication (DRY)
4 Rules of
It’s not about code duplication, it’s about
knowledge duplication. Don’t repeat yourself.
Every piece of knowledge should have one and
only one representation.
3

23. Simple Design
Small
4 Rules of
Has fewer classes, modules, packages. Any not-
used code should be deleted. You should also
check missing or duplicate abstractions. Over-
extraction should also be not allowed.
4

24. http://blog.thecodewhisperer.com/2013/12/07/putting-an-age-old-battle-to-rest
“Putting an Age-Old Battle to Rest” by Joe Rainsberger
The Simple Design Dynamo

25. TDDWrite exactly one new test1
2 Run the test to make sure it fails
3 Write least amount of code to make the test pass
4 Refactor to remove duplication
5 Repeat the process
Test Driven Development
Test Driven Design
Test First Development

26. Zero-player game
Cellular automation system
Devised by John Horton Conway
Evolution is determined by initial state
Each cell can be alive or dead
Conway’s Game of Life
Problem to solve:

27. Each cell has 8 neighbours
and follows 3 rules
1 2 3
4
567
8

28. Any live cell with fewer than 2 live neighbours
dies of loneliness
Rule 1

29. Any live cell with more than 3 live neighbours
dies of overcrowding
Rule 2

30. Any dead cell with exactly 3 live neighbours
comes to life of warmth
Rule 3

31. Avoid to use primitives
Avoid to use conditional conditions (if, ?:, switch)
Avoid to use loops (while, for)
All methods return void
Max 5 lines of code per method
Verbs instead of nouns
Ping pong programming
Mute ping pong programming
Swap computers
Do not use mouse
Variations

32. ENJOYremember
whatever you do
do not forget to
https://www.flickr.com/photos/fraserspeirs/3394902061
Joe O'Brien and Jim Weirich while doing ruby code review

33. sessions
let the
begin
We select 6 activities amoung the activities list after checking
TDD and pair programming experiences of the attendees.
Every coderetreat has its own set of activities.

34. No constraints
Do your best

35. Ping-pong pair programming

36. No primitives
Use only immutable objects

37. No primitives
No conditionals
Max 5 lines of code

38. No way to return any value
Verbs instead of Nouns

39. Mute ping-pong

40. What, if anything, did you learn today?
What, if anything, surprised you today?
What, if anything, will you do differently?
closing

41. https://leanpub.com/4rulesofsimpledesign
The only thing we truly know about
software development is that we can
expect changes to our system. Through
concrete examples, let's explore ways
to build flexible, adaptable software
systems by better understanding Kent
Beck's 4 Rules of Simple Design.
Book from
Corey Haines
Published at LeanPub on 2014

42. http://www.coderetreat.org
Coderetreat Community Network
http://blog.zilverline.com/2013/12/20/facilitating-the-global-day-of-coderetreat-2013-in-amsterdam
Facilitating the Global Day of Coderetreat 2013 in Amsterdam
http://www.alexbolboaca.ro/wordpress/articles/how-to-organize-a-code-retreat
How to organize a code retreat
Coderetreat Facilitator Training
https://vimeo.com/54519386
https://leanpub.com/4rulesofsimpledesign
Understanding the 4 Rules of Simple Design

43. Lemİ orhan ergİn
Founder & Author @ agilistanbul.com
lemiorhan@agilistanbul.com
@lemiorhan
https://www.linkedin.com/in/lemiorhan
@lemiorhan
https://twitter.com/lemiorhan
@lemiorhan
https://github.com/lemiorhan
@lemiorhan
http://www.slideshare.net/lemiorhan
agile software craftsman
agilistanbul.com
Turkish blog about agile development
lemiorhanergin.com
Official site having personal information