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@fernando_cejas
TECHNICAL DEBT
GURU LEVEL
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I am Fernando Cejas
I am here because I love to share
experiences and disasters I have
made in my professional life.
× Twitter: @fernando_cejas
× Github: @android10
× Blog: fernandocejas.com
Hello!
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“BAD CODE IS
ALWAYS
imprudent”
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In an ideal world...every project...
Finished
on time
Clean
code
On
budget
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Even better… our perfect project...
Additional
features
Tested
twice
???
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Level
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FACT: OUR SOFTWARE
IS TERRIBLE!!!
And that does not make it special.
All software is terrible, and yes, we know
it is definitely TRUE
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WHAT IS LEGACY CODE?
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Code without tests
Code that someone else has written
ANTI-PATTERNS
No separation of concerns
Code difficult to change
Difficult to understand
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WHAT IS RECKLESS DEBT?
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Code that violates
design principles
Without even a short term payoff
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WHAT IS TECHNICAL DEBT?
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It is a metaphor
doing things the quick and dirty way sets us up with a
technical debt
Incurs INTEREST PAYMENT
which come in the form of the extra effort that we have
to do in future development because of the quick and
dirty design choice.
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Technical debt is the
additional effort and
work REQUIRED to
complete any software
development.
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“TEchnical debt
is reflected on
legacy code”
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Real case scenario:
ADDING A NEW
FEATURE
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THE “EASY”
WAY:
Built up with messy
design and code, will
get you there faster.
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THE “HARD”
WAY:
Built up with cleaner
design and code, that
takes a lot more time
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“Accept some
technical debt
for tactical
reasons”
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DETECTING
TECHNICAL DEBT
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Level
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STATIC CODE
ANALYSIS
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Static CODE ANALYSIS: CODE METRICS
Cyclomatic
complexity
complexity of classes and
methods by analyzing the
number of functional paths in
the code
Code coverage
A lack of unit tests is a source
of technical debt. This is the
amount of code covered by
unit tests.
Bug count
As technical debt increases,
quality of the software
decreases. The number of bugs
will likely grow.
Number of rule
violations
Number of rules violated from a
given set of coding
conventions.
SQALE-rating
Broad evaluation of software
quality. The scale goes from A
to E, with A being the highest
quality.
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Level
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TECH DEBT
RADAR
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TECH
DEBT
RADAR
+PAIN
-PAIN
+Dev TIME
-Dev TIME
DI
Login
Player
UI
Layer
Photos
Share
Data
Layer
Search
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Level
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BEHAVIORAL CODE
ANALYSIS
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“TEchnical debt
is reflected on
legacy code”
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“TEchnical debt
is NOT ONLY
reflected on
legacy code”
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BEHAVIORAL CODE ANALYSIS:
1. Consider the organization and people side of the system.
2. This gives you valuable information that is invisible in the
source code itself, such as measures of team autonomy and
off-boarding risks.
3. How developers interact with the code.
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behavioral CODE ANALYSIS: METRICS
Hotspots
Hotspots identify the modules with
most development activity -- often
technical debt.
Code biomarkers
Code Biomarkers aim to indicate
specific properties at very low code
level.
Refactoring Targets
Prioritize improvements to these files
since they have the highest technical
debt interest rate.
Change coupling
Change coupling helps us
uncover implicit change
patterns in our code.
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EXTRA BALL!!
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PAYING
TECHNICAL DEBT
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Paying debt at team level:
1. Prioritize and keep track of it.
2. Allocate time to address it.
3. Technical Debt days.
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Paying debt at COMPANY level:
1. Educate people about its existence.
2. Make it transparent.
3. Communicate it properly.
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Paying debt at COMPANY level:
COST OF DELAY
This (mostly manual) metric helps to make visible
how much time a team loses due to technical
debt.
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SOME DAYS YOU CANNOT GET RID
OF A BOMB...
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THANKS!
Any questions?
You can find me at @fernando_cejas (twitter) & @android10 (github)
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Credits
Special thanks to all the people who made and
released these awesome resources for free:
× Presentation template by SlidesCarnival
× Photographs by Startupstockphotos