The document discusses key programming principles including 'Don't Repeat Yourself' (DRY), 'Keep It Simple, Stupid' (KISS), and 'You Ain't Gonna Need It' (YAGNI), emphasizing the balance between abstraction and simplicity in coding. It also outlines root cause analysis (RCA) techniques for problem-solving, distinguishing between reactive and proactive management approaches. Ultimately, the text advocates for sustainable coding practices and logical dependencies in software development.

1. CLEAN(ER) CODE
TECH ’N‘ DRINKS

2. ABOUT ME
MARTIN “D4RK” STRAUB
▸ iOS developer @myposter !
▸ Guitar player @kentuckyschreit (ska/pop-punk) 🎸
▸ Husband 💑
▸ Cat 😺

7. ABOUT ME
MARTIN “D4RK” STRAUB
▸ ...
▸ ...
▸ martin-straub.de
▸ iOS developer @myposter !
▸ Guitar player @kentuckyschreit (ska/pop-punk) 🎸
▸ Husband 💑
▸ Cat 😺

8. DRY
DON’T REPEAT YOURSELF

9. EVERY PIECE OF KNOWLEDGE MUST HAVE
A SINGLE, UNAMBIGUOUS, AUTHORITATIVE
REPRESENTATION WITHIN A SYSTEM.
The Pragmatic Programmer
DON’T REPEAT YOURSELF (DRY)

10. DON’T REPEAT YOURSELF (DRY)
WHAT’S IT ABOUT?
▸ Don’t repeat the knowledge
▸ Avoid contradictions
▸ One source of truth

11. DON’T REPEAT YOURSELF (DRY)
TYPES OF DUPLICATION
▸ Imposed duplication
▸ Inadvertent duplication
▸ Impatient duplication
▸ Interdeveloper duplication

12. DUPLICATION IS FAR
CHEAPER THAN THE
WRONG ABSTRACTION.
Sandi Metz
(Teacher, writer, consultant, programmer)

13. A SYSTEM’S KNOWLEDGE IS FAR
BROADER THAN JUST ITS CODE.
DON’T REPEAT YOURSELF (DRY)
The Pragmatic Programmer

14. DON’T REPEAT YOURSELF (DRY)
BROADER USAGE
▸ Database schemas
▸ Test plans
▸ Build system
▸ Documentation

15. KISS
KEEP IT SIMPLE, STUPID

16. KEEP IT SIMPLE STUPID
Kelly Johnson
(Lead engineer at Lookheed Martin)

17. KEEP IT SIMPLE, STUPID (KISS)
WHAT’S IT ABOUT?
▸ Most systems work best if they are kept simple
rather than made complicated
▸ Simplicity should be a key goal in design
▸ Unnecessary complexity should be avoided
▸ The end-user doesn’t care how smart you are
▸ If you have to explain the product, it’s too
complicated

18. MAKE EVERYTHING AS SIMPLE AS
POSSIBLE, BUT NOT SIMPLER
Albert Einstein
KEEP IT SIMPLE, STUPID (KISS)

19. YAGNI
YOU AIN’T GONNA NEED IT

20. YOU AIN’T GONNA NEED IT (YAGNI)
WHAT’S IT ABOUT?
▸ 80% of the time spent on a software project is
invested in 20% of the functionality
▸ Prioritize (MoSCoW)
▸ No future coding
▸ No overengineering

21. MUST HAVE
SHOULD HAVE
COULD HAVE
WON’T HAVE (THIS TIME)
MoSCoW principle

22. DRY VS. KISS & YAGNI
SUMMARY
▸ DRY strives for abstraction
▸ KISS aims for simplicity
▸ YAGNI doesn’t want to do it at all
▸ Those principles compete with each other
▸ Find the right balance between DRY and KISS/
YAGNI

23. RCA
ROOT CAUSE ANALYSIS

24. …USE A BUCKET!
WATER DRIPS FROM THE
CEILING?

25. …RIGHT?! 🧐

26. SOLVE PROBLEMS
THERE ARE 2 WAYS TO

27. ROOT CAUSE ANALYSIS (RCA)
1. REACTIVE MANAGEMENT
▸ React quickly, by treating the symptoms
▸ Goal: Ease the effects of the problem as soon
as possible

31. ROOT CAUSE ANALYSIS (RCA)
2. PROACTIVE MANAGEMENT
▸ Address the real cause instead of its symptoms
▸ Goal: Prevent problems from (re-)occurring

32. ROOT CAUSE ANALYSIS (RCA)
ROOT CAUSE ANALYSIS
▸ Identification and description
▸ Chronology
▸ Differentiation
▸ Causal graphing
▸ Next step: Trigger long-term corrective actions

33. BY REPEATING WHY FIVE TIMES, THE
NATURE OF THE PROBLEM AS WELL AS
ITS SOLUTION BECOMES CLEAR.
Taiichi Ohno
ROOT CAUSE ANALYSIS (RCA)
(“Father” of the Toyota Production System)

34. ROOT CAUSE ANALYSIS (RCA)
5 WHYS
Example: Ran through a red light. (problem)
▸ Why? - Late for work. (1st why)
▸ Why? - Woke up late. (2nd why)
▸ Why? - Alarm clock didn’t ring. (3rd why)
▸ Why? - Battery was empty. (4th why)
▸ Why? - Forgot to charge it. (5th why and root
cause)

35. ROOT CAUSE ANALYSIS (RCA)
CONCLUSION
▸ Reactive management: quickly ease the
symptoms
▸ Proactive management: actually fix the issue
▸ Only the latter can lead to a sustainable and
reliable code base

36. WANT SOME MORE?!

37. MAKE IT WORK,
MAKE IT RIGHT,
MAKE IT FAST.
Kent Beck
(Software engineer, creator of extreme programming, TDD, …)

38. IT’S HARDER TO READ
CODE THAN TO WRITE IT.
Joel Spolsky
(Co-founder of Stack Overflow)

39. BUILD YOUR LOGIC ON
DIRECT RELATIONS, NOT
ON ASSUMPTIONS.
Unknown author

40. LOGIC DEPENDENCIES
EXAMPLES
▸ App: Does the UI depend on the device’s
orientation?
... or on parent view changes?
▸ Do you grab yourself a new beer every 15
minutes?
… or every time the bottle’s empty?

41. SUMMARY
CLEAN(ER) CODE

42. CLEAN(ER) CODE
SUMMARY
▸ Play the principle game
▸ BUT:
▸ Principles are not rules
▸ Find the right balance
▸ Always use common sense
▸ Don’t get paralysed by overthinking things

43. SOURCES
CLEAN(ER) CODE

44. SOURCES
TITLE & ABOUT ME
▸ https://twitter.com/ColucciLaw/status/1010920761043939328
▸ martin-straub.de
▸ https://www.instagram.com/maezikatzi

45. SOURCES
DON’T REPEAT YOURSELF (DRY)
▸ https://pragprog.com/book/tpp/the-pragmatic-programmer
▸ https://thevaluable.dev/dry-principle-explained
▸ http://verraes.net/2014/08/dry-is-about-knowledge
▸ https://www.sandimetz.com/blog/2016/1/20/the-wrong-abstraction

46. SOURCES
DRY (IMAGES)
▸ https://www.flickr.com/photos/liveoncelivewild/32686776783
▸ https://medium.com/startup-grind/even-smart-vcs-invest-in-cross-industry-
clones-6a3c63f830e4
▸ https://www.engadget.com/2016/07/27/dolly-sheep-clones-are-healthy
▸ https://www.writermag.com/writing-inspiration/the-writing-life/declutter-
hoarded-story-ideas

47. SOURCES
KEEP IT SIMPLE, STUPID (KISS)
▸ https://en.wikipedia.org/wiki/Kelly_Johnson_(engineer)
▸ https://www.interaction-design.org/literature/article/kiss-keep-it-simple-stupid-
a-design-principle
▸ https://championingscience.com/2019/03/15/everything-should-be-made-as-
simple-as-possible-but-no-simpler

48. SOURCES
KISS (IMAGES)
▸ https://archive.triblive.com/aande/music/kiss-makeup-has-changed-but-their-
impact-remains-strong
▸ https://mannerofspeaking.org/2018/03/11/simplicity-is-the-key-to-brilliance
▸ https://mostlyme-certainothers.com/2015/07/16/no-frills/simplicity-01

49. SOURCES
YOU AIN’T GONNA NEED IT (YAGNI)
▸ https://ronjeffries.com/articles/019-01ff/iter-yagni-skimp
▸ https://en.wikipedia.org/wiki/You_aren%27t_gonna_need_it
▸ https://en.wikipedia.org/wiki/MoSCoW_method

50. SOURCES
YAGNI (IMAGES)
▸ https://www.monkeyuser.com/2019/yagni
▸ https://www.developgoodhabits.com/80-20-rule
▸ http://www.thebluediamondgallery.com/wooden-tile/p/priority.html
▸ https://xkcd.com/974

51. SOURCES
ROOT CAUSE ANALYSIS (RCA)
▸ https://en.wikipedia.org/wiki/Root_cause_analysis
▸ https://en.wikipedia.org/wiki/5_Whys
▸ https://en.wikipedia.org/wiki/Taiichi_Ohno
▸ https://kanbanize.com/lean-management/improvement/5-whys-analysis-tool

52. SOURCES
RCA (IMAGES)
▸ https://twitter.com/moksony/status/809695818223681536
▸ https://www.sueddeutsche.de/muenchen/nahverkehr-darum-tropft-es-beim-s-
bahn-gleis-am-marienplatz-1.3330650
▸ https://www.br.de/nachrichten/bayern/s-bahn-chaos-in-muenchen-stoerung-
nach-wassereintritt-dauert-an,RYNZ6Kw
▸ https://twitter.com/sabbiafilms/status/912692514519502849
▸ https://www.monkeyuser.com/2018/final-patch

53. SOURCES
RCA (IMAGES) 2
▸ https://www.jaguarforums.com/forum/x-type-x400-14/multiple-codes-read-
puter-106645
▸ https://psychologyhumor.tumblr.com/post/165200208492/express-
psychotherapy
▸ https://michaelwtravels.boardingarea.com/2015/06/airline-fix-plane-duct-
tape-uses/travelnews-111
▸ https://www.solarwindsmsp.com/blog/results-show-controlnow-can-make-
department-proactive

54. SOURCES
RCA (IMAGES) 3
▸ https://www.monkeyuser.com/2018/root-cause
▸ https://medium.com/@m.azeem111/why-statement-c2a5b1f8b0fa
▸ https://brightpast.com/how-to-use-social-media-for-proactive-reputation-
management

55. SOURCES
MAKE IT WORK, MAKE IT RIGHT, MAKE IT FAST.
▸ https://www.thetombomb.com/2018/05/17/make-it-work-make-it-right-make-
it-fast
▸ http://engineerspro.blogspot.com/2016/06/career-information-regarding-
mechanical.html
▸ https://www.pixwords.solutions/tl/solution/pagliko
▸ https://www.donanimhaber.com/spacex-falcon-roketine-ait-parcanin-dunya-ya-
dustugu-anin-videosunu-yayinladi--115810

56. SOURCES
IT’S HARDER TO READ CODE THAN TO WRITE IT.
▸ https://www.joelonsoftware.com/2000/04/06/things-you-should-never-do-
part-i

57. SOURCES
BUILD YOUR LOGIC ON DIRECT RELATIONS, NOT ON ASSUMPTIONS.
▸ https://www2.le.ac.uk/institution/lias/images/Fellows%203.jpg/view
▸ https://medium.com/@CodementorIO/good-developers-vs-bad-developers-
fe9d2d6b582b

58. SOURCES
SUMMARY & SOURCES
▸ https://code.tutsplus.com/tutorials/3-key-software-principles-you-must-
understand--net-25161
▸ https://en.wikipedia.org/wiki/Analysis_paralysis
▸ https://www.mr-maid.com/blog/hiring-bad-cleaning-service
▸ https://www.acadoo.de/woran-erkenne-ich-serioese-quellen.html
▸ https://en.wikipedia.org/wiki/LOLCODE

59. KTHXBYE
CLEAN(ER) CODE