Prototypes are forever: Evolving from a prototype project to a full-featured
system
Alexandre FreireFernando FreireHugo CorbucciMariana Bravo
Introduction
Why should we throw our prototypes away?
Introduction
Why is technical debt considered harmful?
Context
3 months prototype RCP project=+ 4 developers
80 pair hours per iteration
Context
3 months prototype RCP project=+ 4 developers
80 pair hours per iteration
Goal: exp
loration and
discove
ry for a
demo
Iteration 1 - 25 commits - Jun/2008
Practices
No full test coverage Only crucial tests→
Practices
Invest in Continuous Deployment (hourly builds)
Practices
“Buggy” software for well-behaved users
Client priorization:● No corner-cases● No validation● No verification● No exception handling● Lots of new features
Iteration 4 - 211 commits - Oct/2008
Ready for demo?
Ready for demo?
No!
Ready for demo?
Needs text editor
Ready for demo?
Needs text editor
Deadline: Dec/2008
Complete focus on the editor
Iteration 6 - 352 commits - Dec/2008
Changing the rules
Demo cancelled!
Changing the rules
Demo cancelled!● Less pressure Fight against technical debt→● January 2009: a whole iteration dedicated to
refactoring
Changing the rules
● 6 months evolving editor features● A complex editor means other less new
features
...● Still no demo
Iteration 12 - 937 commits - Jun/2009
This is no longer a prototype
Dedicated study group
of dramaturgy experts● More ideas for new features● Investment in UX
This is no longer a prototype
Outsourcing editor so team can focus on new features
Tracking Technical Debt
Tracking Technical Debt
Difficulties
GUI testing
Loss of a team member
Difficulties
Prioritizing integration VS new features● Integration with outsource team● No steady rhythm
New direction
“I've invested too much!
This software is mine.”
New direction
“I've invented something new.”
New direction
Focus on quality
Aim for complete, bug-free features
Iteration 23 - 2005 commits - now
Conclusion
No need to throw away prototypes:
just write tests for crucial elements
and refactor mercilessly
Conclusion
Technical debt is acceptable if kept under control and software delivers value for client
Conclusion
Throw away if all you wanted was to gain knowledge
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