1. Sven Peters / Atlassian
Wenn Code altert
Tipps, wie Wartungsprojekte frisch bleiben

2. Sven Peters
Ambassador
@svenpet
svenpet.com
mobro.co/svenpet

3. Disclaimer
my
Experience
@svenpet
svenpet.com

4. “ Nothing has a more profound or long-
lasting negative effect on the productivity
of a software team than a mess. Nothing.
Robert C. Martin
“

5. ?
Maintenance
projekt

6. ?
5 years

7. lin
? 1M+
es
of
co
de

8. lin
? es
2M+
of
co
de

9. ?
lost
overview
de
co
of
es
lin

10. Har
Bath Tub Curve
dw
a re

11. Sof
Bath Tub Curve
twa
re

12. Sof
Bath Tub Curve
twa
re

13. Field
green

14. How long does it take?
8 hours
no Tests!
grüne
We need it in 6!
Wiese
OK, I‘ll do it in 4!

17. more cooks!

18. too many cooks...
...spoil the broth

19. REWRITE

21. REWRITE

22. e n
ro k
B Windows

25. Don‘t stop
the Engines

26. THE DEVELOPER
THE MANAGER
THE SCRUM MASTER
There is
no Plan B

27. Boy Scout Rule
Leave the campground cleaner than you
found it.

28. Toolchain
The

30. readability
improve

31. Naming
“ Any fool can write code that ahumans cancan understand. Good
computer
programmers write code that understand. “
Martin Fowler

32. no
comment

33. test
automated

34. Legacy Code Change Algorithm by Michael C. Feathers
1. Identify Change Points
2. Make Changes and Refactor

35. Legacy Code Change Algorithm by Michael C. Feathers
1. Identify Change Points
2. Find Test Points
3. Break Dependencies
4. Write Tests
5. Make Changes and Refactor

36. Clean Code

37. ingle Responsible Principle
pen Closed Principle
iskow Substitution Principle
nterface Segregation Principle
ependency Inversion Principle

39. Root Ca
usposition over Inheritaince
Favour Com e Analysis rself on
ract
you NeedtIt
Yout Aep‘t Gt nna bsrns
in eao
Do n‘ r onA e
C of c
DRYKISSperation of el
Se - Kee ev
p etLs
i im
ingl ple, s
S tupid

40. Clean Code
Developer
von
Stefan Lieser &
Ralf Westphal
clean-code-developer.de

41. Evolve
Clean Code
&
Developer

45. Sven Peters
Atlassian
@svenpet