Presents the benefits and dangers of prototypes. We're talking about creating prototypes to speed up the validation of an idea but being careful enough not to keep the quick and crappy result as the end result of work.

1. Prototypes are forever:
Evolving from a prototype
project to a full-featured
system
Alexandre Freire
Fernando Freire
Hugo Corbucci
Mariana Bravo

2. Introduction
Why should we throw our prototypes
away?

3. Introduction
Why is technical debt considered
harmful?

4. Context
+ 4 developers
80 pair hours per iteration
=
3 months prototype RCP project

5. Context
and
+
on m4 developers
ti e
o
ra 80 pair hours per iteration
o ad
pl or
ex y f
l: er
=
a v
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G c
dis
3 months prototype RCP project

6. Iteration 1 - 25 commits - Jun/2008

7. Practices
No full test coverage → Only crucial tests

8. Practices
Invest in Continuous Deployment (hourly builds)

9. Practices
“Buggy” software for well-behaved users
Client priorization:
● No corner-cases
● No validation
● No verification
● No exception handling
● Lots of new features

10. Iteration 4 - 211 commits - Oct/2008

11. Ready for demo?

12. Ready for demo?
No!

13. Ready for demo?
Needs text editor

14. Ready for demo?
Needs text editor
Deadline: Dec/2008
Complete focus on the editor

15. Iteration 6 - 352 commits - Dec/2008

16. Changing the rules
Demo cancelled!

17. Changing the rules
Demo cancelled!
● Less pressure → Fight against technical debt
● January 2009: a whole iteration dedicated to
refactoring

18. Changing the rules
● 6 months evolving editor features
● A complex editor means other less new
features
...
● Still no demo

19. Iteration 12 - 937 commits -
Jun/2009

20. This is no longer a prototype
Dedicated study group
of dramaturgy experts
● More ideas for new features
● Investment in UX

21. This is no longer a prototype
Outsourcing editor so team can focus
on new features

22. Tracking Technical Debt

23. Tracking Technical Debt

24. Difficulties
GUI testing
Loss of a team member

25. Difficulties
Prioritizing integration VS new features
● Integration with outsource team
● No steady rhythm

26. New direction
“I've invested too much!
This software is mine.”

27. New direction
“I've invented something new.”

28. New direction
Focus on quality
Aim for complete, bug-free features

29. Iteration 23 - 2005 commits - now

30. Conclusion
No need to throw away prototypes:
just write tests for crucial elements
and refactor mercilessly

31. Conclusion
Technical debt is acceptable if kept under control
and software delivers value for client

32. Conclusion
Throw away if all you wanted was to gain
knowledge

33. Questions?
contact@agilbits.com.br