Oredev :: The Technical Debt Trap

The Technical Debt Trap Michael J Norton @DocOnDev LeanDog LLC* *The views expressed are not necessarily the views of LeanDog LLC (but they could be)

Rant.begin

What is Technical Debt?

What is Technical Debt? Ward Cunningham oopsla’92

What is Technical Debt? Ward Cunningham Shipping ﬁrst time code is like going into debt. oopsla’92

What is Technical Debt? Ward Cunningham Shipping ﬁrst time code is like going into debt. A little debt speeds development so long as it is paid back promptly with a rewrite. oopsla’92

What is Technical Debt? Ward Cunningham The danger occurs when the debt is not repaid. Every minute spent on not- quite-right code counts as interest on that debt. oopsla’92

Technical Debt is a Good Idea

Technical Debt is a Good Idea WTF?

Technical Debt is a Good Idea Strategic Design Decision

Technical Debt is a Good Idea Strategic Design Decision Allow for Rapid Delivery To Ellicit Quick Feedback And Correct Design

Technical Debt is a Metaphor Here Be Danger

Metaphors Rock We reason by analogy Can’t keep running at this pace Building on a weak foundation Puts pressure on It’s raining men our design

Metaphors Rock We reason by analogy Can’t keep running at this pace Building on a weak foundation Puts pressure on It’s raining men our design (hallelujah)

Metaphorphosis When Metaphors go wrong Prudent

Metaphorphosis When Metaphors go wrong Return on Investment Short-Term Fraudulent Credit Card Inadvertent RecklessScheme Pyramid Debt Auto Loan High Interest in the Third Quadrant Home Loan Voluntary Intentional Loan Shark Long-Term Prudent Student Loan Pragmatic Leverage Operational

Metaphorphosis

Metaphorphosis When Metaphors go wrong “cut a lot of corners” James Shore http://jamesshore.com/Blog/CardMeeting/Voluntary-Technical-Debt.html “quick and dirty” Martin Fowler “sloppy” http://www.martinfowler.com/bliki/TechnicalDebt.html David Laribee “just hack it in” http://msdn.microsoft.com/en-us/magazine/ee819135.aspx Steve McConnell http://blogs.construx.com/blogs/stevemcc/archive/2007/11/01/technical-debt-2.aspx

Technical Debt Quadrant http://martinfowler.com/bliki/TechnicalDebtQuadrant.html

That’s not what I said Ward Cunningham [Many] have explained the debt metaphor and confused it with the idea that you could write code poorly with the intention of doing a good job later. http://www.youtube.com/watch?v=pqeJFYwnkjE&feature=player_embedded youtube.com 2009

That’s not what I said Ward Cunningham ... confused it with the idea that you could write code poorly ... youtube.com 2009

Clean Code is Required Ward Cunningham The ability to pay back debt [...] depends upon you writing code that is clean enough to be able to refactor as you come to understand your problem. youtube.com 2009

Dirty Code is a Bad Idea Ward Cunningham Dirty code is to technical debt as the pawn broker is to ﬁnancial debt. Don't think you are ever going to get your code back. http://twitter.com/WardCunningham/status/3742903303 twitter 2009

Is it Technical Debt? Ask yourself... Is the code clean? Is the code tested? Is there a learning objective? Is there a plan for payback? Is the business truly informed?

Is it Technical Debt? If you said no to even one Is the code clean? Is the code tested? Is there a learning objective? Is there a plan for payback? Is the business truly informed? Then you don’t have Technical Debt

You have a mess Mess (noun) 1. Disorderly accumulation, heap, or jumble 2. A state of embarrassing confusion 3. An unpleasant or difﬁcult situation

You have cruft Cruft (noun) 1. An unpleasant substance 2. The result of shoddy construction 3. Redundant, old or improperly written code

Chill. It’s just semantics, man.

Chill. It’s just semantics, man. JUST Semantics? Technical Debt is Good

Chill. It’s just semantics, man. JUST Semantics? Quick and Dirty is Technical Debt is Good

Chill. It’s just semantics, man. JUST Semantics? Quick and Dirty is Good

Technical Debt Quadrant

Technical Debt Quadrant “Let’s deploy and gather more information.”

“Technical Debt” in Other Industries Construction http://www.constructionmanagementschools.net/wp-content/uploads/2010/04/construction-mistakes-18.jpg

“Technical Debt” in Other Industries Construction Reckless and Deliberate http://www.constructionmanagementschools.net/wp-content/uploads/2010/04/construction-mistakes-18.jpg

“Technical Debt” in Other Industries Automotive http://www.weirdomatic.com/wp-content/pictures/2010/07/quick-car-ﬁx.jpg

“Technical Debt” in Other Industries Automotive Reckless and Deliberate http://www.weirdomatic.com/wp-content/pictures/2010/07/quick-car-ﬁx.jpg

“Technical Debt” in Other Industries Medical http://www.scientiﬁcamerican.com/media/inline/blog/Image/MedicalError.jpg

“Technical Debt” in Other Industries Medical Reckless and Inadvertent http://www.scientiﬁcamerican.com/media/inline/blog/Image/MedicalError.jpg

Technical Debt Quadrant “Let’s deploy and gather more information.”

Technical Debt Quadrant ible “Let’s deploy and ns gather more o sp information.” Ir re

Technical Debt Quadrant ible “Let’s deploy and ns gather more o sp information.” Ir re n t e te m p In co

Technical Debt Quadrant le ic al s ib “Let’s deploy and n h t o n gather more ec eb sp information.” T Ir re D n t e te m p In co

Messy Code is a Bad Decision Every Time

Messy Code is a Bad Decision Every Time You are a professional developer (Professionals behave ethically)

Messy Code is a Bad Decision Every Time You are a professional developer (Professionals behave ethically) You are going to create unintentional cruft (You can’t help it. It’s unintentional.)

Messy Code is a Bad Decision Every Time You are a professional developer (Professionals behave ethically) You are going to create unintentional cruft (You can’t help it. It’s unintentional.) You have to clean up the existing cruft (Intent doesn’t alter Responsibility)

Grammy Doesn’t Love Me! Setting Expectations

The Trap Mess begets mess

The Trap Mess begets mess Precedent for Speed over Quality Expectation of increased velocity Mess slows you down Must generate more mess to keep up

The Trap Mess begets mess Precedent for Speed over Quality Expectation of increased velocity Mess slows you down Must generate more mess to keep up Ask permission to do your job correctly

Avoid The Trap Incremental Fixes Fail http://www.jacoozi.com/blog/wp-content/uploads/2007/01/refactoring_coc_big.jpg

Avoid The Trap Clean Constantly

Avoid The Trap Clean Constantly Never make an intentional mess Monitor your “Technical Debt” Follow the Boy Scout Rule Quality is your responsibility

Avoid The Trap Clean Constantly Never make an intentional mess Monitor your “Technical Debt” Follow the Boy Scout Rule Quality is your responsibility NEVER ask permission to do your job correctly

Monitoring Cruft/Debt A few key metrics

Monitoring Cruft/Debt A few key metrics Code Coverage Cyclomatic Complexity Coupling

Monitoring Cruft/Debt Code Coverage

Monitoring Cruft/Debt Code Coverage Code exercised by automated tests Monitor test types separately Don’t set a coverage target 100% Coverage is a smell

Monitoring Cruft/Debt Code Coverage Code exercised by automated tests Monitor test types separately Don’t set a coverage target 100% Coverage is a smell Monitor trends, not points

Monitoring Cruft/Debt Cyclomatic Complexity

Monitoring Cruft/Debt Cyclomatic Complexity Number of logical branches in code Direct relationship with bugs Typically high in concentrated areas Reduce Conditionals

Monitoring Cruft/Debt Cyclomatic Complexity Number of logical branches in code Direct relationship with bugs Typically high in concentrated areas Reduce Conditionals Monitor trends, not points

Monitoring Cruft/Debt Coupling

Monitoring Cruft/Debt Coupling Interconnectedness of systems High Coupling = Difﬁcult to Change Afferent (Toward) and Efferent (Away) Dependency Injection

Monitoring Cruft/Debt Coupling Interconnectedness of systems High Coupling = Difﬁcult to Change Afferent (Toward) and Efferent (Away) Dependency Injection Monitor trends, not points

Review Technical Debt Cruft

Review Technical Debt Is a strategic design decision Requires the business to be informed Requires a pay-back plan - (Clean Code) Cruft

Review Technical Debt Is a strategic design decision Requires the business to be informed Requires a pay-back plan - (Clean Code) Cruft Happens Needs to be monitored and cleaned Is (probably) NOT Technical Debt

Rant.end

Thank You! The Technical Debt Trap Michael J Norton @DocOnDev LeanDog LLC* doc@leandog.com *The views expressed are not necessarily the views of LeanDog LLC (but they could be)

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Oredev :: The Technical Debt Trap

by Michael "Doc" Norton on Nov 21, 2010

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