Where Bad Code Comes From

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Where Bad Code Comes From? June 2012

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I’m Marcin Floryan http://marcin.ﬂoryan.pl

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Energized Work @mﬂoryan Value, Flow, Quality You can ﬁnd me at:

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The ACE Conference: This presentation: #aceconf #mfbadcode

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Acceptance criteria You can give examples of different sources of bad code You have identiﬁed one new reason for bad code you didn’t pay attention to before You will consider a way to tackle it ☐ ☐ ☐

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Any developers in the room?

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Seen any bad code?

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? Experienced

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No content

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? how bad can it get

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Mariner 1 $18.5 million

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Hartford Coliseum $80 million

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Ariane 5 $500 million

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“One bug, one crash. Of all the careless lines of code this one may stand as the most devastatingly efﬁcient. James Gleick

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North America black-out 55 million people

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“To err is human, but to really foul things up you need a computer. Paul Ehrlich

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Does your code resemble

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or this…?

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Building

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Building

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what how code

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“When people are factored in, nothing is simple. Ken Schwaber

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what how who code

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“A post-modern ﬁrm is rich in information and relies heavily on the daily choices of its knowledgeable employees. Haridimos Tsoukas

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Let’s go back in time

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What’s that rustling in the bushes?

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FIGHT

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You’re fed

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What’s that rustling in the bushes?

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No content

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F IGHT L

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You’re safe

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back to reality

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How about that RAG report?

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Running late?

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Add more people

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Even more late * * Consult the Brooks Law for details

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How about that RAG report?

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Already over budget?

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Let’s squeeze the testing

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What do you mean quality?

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But it worked so well

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Do you ever ﬂy?

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? a novice pilot

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or perhaps even

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Welcome aboard KLM Flight 4805

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A bomb in a ﬂower shop

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Landing at Tenerife

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law mandated rest period looming

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decision to re-fuel

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and a T H I C K fog

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KLM 747 crashes

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Communication misunderstandings deadliest accident in aviation history

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Junior pilots any better? remember Air France ﬂight 447

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so how about

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? Ever worked

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? Ever worked

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? Ever worked

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meet Bob*

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“Good, safe social interaction is as necessary to successful development as good technical skills Kent Beck

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Difﬁcult Conversations

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Recognise

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How do we tell… our tester you let all these nasty bugs through

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How do we tell… a new developer you don’t know the framework well enough

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How do we tell… project manager we are not resources

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How do we tell… stakeholders your expectaAons are unrealisAc

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How do we tell… operations we need it live NOW

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How do we tell… our client I am unable to add value as a coach

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we DON’T.

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instead

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Time for

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Ehm… no.

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I want you to learn

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“One must learn by doing the thing; for though you think you know it, you have no certainty, until you try. Sophocles

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so instead

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some

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Your job 1.  Find some bad code 2.  Trace it back to a difﬁcult conversation 3.  How could you have done it differently?

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My example 1.  Data transfer via FTP upload of text ﬁles is really clunky 2.  That’s the way things are done around here. We never challenged this. 3.  Ask to understand rationale behind the decision, present viable alternatives

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Follow-Up •  Catch me, stop me, talk to me •  Contact me on twitter @mﬂoryan •  Submit and discuss your ideas bit.ly/ace-homework

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The Remember Slide • We’re not optimised for writing code • Our mental software is mostly legacy code • We don’t talk to each other • We hide our emotions

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Bibliography

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So Thank You bit.ly/ace-bad-code

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Resources •  Hartford Civic Center Arena Roof Collapse http://www.eng.uab.edu/cee/faculty/ndelatte/case_studies_project/Hartford%20Civic%20Center/hartford.htm •  Mariner 1 http://en.wikipedia.org/wiki/Mariner_1 •  Ariane 5 http://www.around.com/ariane.html •  KLM ﬂight 4805 http://en.wikipedia.org/wiki/Tenerife_airport_disaster •  Air France ﬂight 447 http://en.wikipedia.org/wiki/Air_France_Flight_447 •  2003 North America black-out http://en.wikipedia.org/wiki/2003_North_America_blackout •  The Kludge Tweet https://twitter.com/jmeydam/status/143405066571886592

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Picture Credits •  The Bismuth Cristals based on “Wismut Kristall und 1cm3 Wuerfel” photo by Alchemist-hp from Wikimedia Commons under FreeArt license •  "FIGURE 02.2 The Manifesto for Agile Software Development” from flickr by Jurgen Appelo from flickr licensed under Creative-Commons-by-2.0 license •  "FIGURE 02.3 The Manifesto for Software Craftsmanship” from flickr by Jurgen Appelo from flickr licensed under Creative-Commons-by-2.0 license •  ”bushes" from flickr by Rupert Ganzer under Creative-Commons-by-nd-2.0 license •  ”Cottontail Rabbit" from flickr by Ken Slade under Creative-Commons-by-nc-2.0 license •  “Lion” from flickr by Angela Huxham under Creative-Commons-by-nc-sa-2.0 license •  ”the first standup" photo from flickr by Karthik Chandrasekariah under Creative-Commons-by-nc-2.0 license •  "Traffic light stacking" photo from flickr by fabi42 under Creative-Commons-by-nc-sa-2.0 license •  “Tenerife747s” picture from Wikimedia Commons by Anynobody under Creative Commons by-sa-3.0 license •  The Difficult Conversations picture is by Olaf Lewitz from XP Days Benelux 2012 available on G+ •  The Coaching Dojo picture is from Olaf Lewitz (By Ole) at XP Days Benelux 2012 available on G+ The remaining pictures are used under the fair use policy or available in public domain.

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