Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
The Dark Art of Debugging
Search
eojthebrave
May 22, 2015
Technology
0
550
The Dark Art of Debugging
A talk about developing the soft-skills required to be a good software debugger.
eojthebrave
May 22, 2015
Tweet
Share
More Decks by eojthebrave
See All by eojthebrave
Altering, Extending, and Enhancing, Drupal 8
eojthebrave
4
970
An Overview of the Drupal 8 Plugin System
eojthebrave
2
410
A Developers Primer to Managing Developers
eojthebrave
0
430
Building Web Services with Drupal 7
eojthebrave
0
400
We Need to Teach People Drupal 8. Now.
eojthebrave
0
300
Thoughts About Presenting
eojthebrave
0
350
Views! Huh? What is it good for?
eojthebrave
1
210
The Incredible Form API
eojthebrave
2
370
Recurring Billing is hard, is hard, is hard.
eojthebrave
2
530
Other Decks in Technology
See All in Technology
生成AI開発案件におけるClineの業務活用事例とTips
shinya337
0
180
モバイル界のMCPを考える
naoto33
0
360
CursorによるPMO業務の代替 / Automating PMO Tasks with Cursor
motoyoshi_kakaku
2
800
事業成長の裏側:エンジニア組織と開発生産性の進化 / 20250703 Rinto Ikenoue
shift_evolve
PRO
1
450
5min GuardDuty Extended Threat Detection EKS
takakuni
0
180
Liquid Glass革新とSwiftUI/UIKit進化
fumiyasac0921
0
300
Amazon Bedrockで実現する 新たな学習体験
kzkmaeda
2
680
Oracle Cloud Infrastructure:2025年6月度サービス・アップデート
oracle4engineer
PRO
2
310
怖くない!はじめてのClaude Code
shinya337
0
300
fukabori.fm 出張版: 売上高617億円と高稼働率を陰で支えた社内ツール開発のあれこれ話 / 20250704 Yoshimasa Iwase & Tomoo Morikawa
shift_evolve
PRO
1
200
KubeCon + CloudNativeCon Japan 2025 Recap by CA
ponkio_o
PRO
0
250
作曲家がボカロを使うようにPdMはAIを使え
itotaxi
0
390
Featured
See All Featured
Build your cross-platform service in a week with App Engine
jlugia
231
18k
Dealing with People You Can't Stand - Big Design 2015
cassininazir
367
26k
Principles of Awesome APIs and How to Build Them.
keavy
126
17k
The Web Performance Landscape in 2024 [PerfNow 2024]
tammyeverts
8
680
Writing Fast Ruby
sferik
628
62k
Done Done
chrislema
184
16k
KATA
mclloyd
30
14k
Visualization
eitanlees
146
16k
Music & Morning Musume
bryan
46
6.6k
GitHub's CSS Performance
jonrohan
1031
460k
The World Runs on Bad Software
bkeepers
PRO
69
11k
Optimising Largest Contentful Paint
csswizardry
37
3.3k
Transcript
The Dark Art of Debugging php[tek] 2015 - Chicago Joe
(@eojthebrave) Shindelar https://joind.in/event/view /3183
Hi. I’m Joe Shindelar @eojthebrave
5 Minutes - GO! + Bugs are inevitable + Debugging
is a science + Replicate, Isolate, Understand, Fix + Practice …
So … where do bugs come from?
Software: Is a set of written instructions provided for a
computer to interpret and use to accomplish a task.
Software: Is a set of written instructions provided for a
computer to interpret and use to accomplish a task. Bugs: Are the defects that arise when those instructions are incorrectly translated.
“There’s a space between zero and one, between the way
the machine counts and thinks and the way we count and think. When you search for explanations for software’s bugs and delays and stubborn resistance to human desires, that space is where you’ll find them.” - Scott Rosenberg -Dreaming In Code
The ONLY way to be a zero bug programmer is
to not write any code.
Debugging is a practical application of both technical skills and
analytical abilities
This presentation is not about tools. But tools play an
important roll in debugging. Learn your tools. Use your tools.
+ Replicate + Isolate + Understand + Fix
Ready? Fire! Aim. Give yourself 10 minutes to jump in
and dirty- debug. But STOP before you go crazy.
STEP ONE Replicate the problem
It is a capital mistake to theorize before one has
data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. - Sherlock Holmes Quote -A Scandal in Bohemia
Replicate + Keep a log
Replicate + Keep a log + Get it to fail
Replicate + Keep a log + Get it to fail
+ Lay a trap
Replicate + Keep a log + Get it to fail
+ Lay a trap + Stimulate. Don’t simulate
Replicate + Keep a log + Get it to fail
+ Lay a trap + Stimulate. Don’t simulate + Automate the failure
Goal: Generate a list of steps
STEP TWO Isolate the problem
There is nothing more deceptive than an obvious fact. -
Sherlock Holmes Quote - The Bascombe Valley Mystery
Isolate + Avoid easter egging
Isolate + Avoid easter egging + Check the plug
Isolate + Avoid easter egging + Check the plug +
Divide & conquer
Isolate + Avoid easter egging + Check the plug +
Divide & conquer + Change one thing at time
Isolate + Avoid easter egging + Check the plug +
Divide & conquer + Change one thing at time + Stop thinking and look
Goal: Explain what is causing the problem to occur. Include
details about application state, time, and inputs.
STEP THREE Understand the problem
Nothing clears up a case so much as stating it
to another person. - Sherlock Holmes Quote - Silver Blaze
Understand + Brain games
Avoid confirmation bias Beware the availability heuristic
Understand + Brain games + Don’t assume anything. Ever
Understand + Brain games + Don’t assume anything. Ever +
Practice tempered humility
Understand + Brain games + Don’t assume anything. Ever +
Practice tempered humility + Read the manual
“Why bother, I can look it up in the Phone
book.” - Einstein
Understand + Brain games + Don’t assume anything. Ever +
Practice tempered humility + Read the manual + Ask for help
Goal: Explain the root cause, and how your proposed fix
will solve the problem.
STEP FOUR Fix the problem
Eliminate all other factors, and the one which remains must
be the truth. - Sherlock Holmes Quote - The Sign of Four
Fix + Don’t stop until you’re done
Fix + Don’t stop until you’re done + Establish causality
Fix + Don’t stop until you’re done + Establish causality
+ Test your fix
Goal: Close the ticket!
+ Replicate + Isolate + Understand + Fix
“The greats weren't great because at birth they could paint.
The greats were great cause they paint a lot.” - Macklemore
The Dark Art of Debugging php[tek] 2015 - Chicago Joe
(@eojthebrave) Shindelar https://joind.in/event/view /3183