Coding Fast and Slow: Applying Kahneman’s Insights to Improve Development Practices and Efficiency
A presentation at DEVNEXUS in in Atlanta, GA, USA by Baruch Sadogursky
Coding Fast and Slow
Baruch Sadogursky - @jbaru ch × Developer Productivity Advocate × Gradle Inc × Development -> DevOps -> #DPE
shownotes × × × × speaking.jbaru.ch Slides Video All the links!
Daniel Kahneman Mar 5, 1934 – Mar 27, 2024
A bat and a ball cost $1.10 in total. The bat costs $1 more than the ball. How much does the ball cost?
How much does the ball cost? C10 + $1.10 = $1.20 C5 + $1.5 = $1.10
Two systems x x x x x Fast Intuitive Automatic Emotional Cheap and eager x x x x x Slow Analytical Controlled Logical Expensive and lazy
Remember the following numb × × × × × ers: 34687 56820 76378 90824 11247 10
You have “mental fuel”
Attention and Capacity Limits in Perception: A Cellular Metabolism Account × × × × BNIRS and oxCCO Cellular Metabolism as Mental Fuel Finite Energy Supply High Load Mode vs Low Load Mode 20
Which system do we use for co d ing? x x x x x Fast Intuitive Automatic Emotional Cheap and Eager x x x x x Slow Analytical Controlled Logical Expensive and Lazy
effortless
27
public class DiscountCalculator { public static void main(String[] args) { calculateDiscount(100, 15); } public static void calculateDiscount(double price, double discount) { double finalPrice = price - (price * discount / 100); System.out.println(“The final price after a ” + discount + “% discount is: ” + finalPrice); } }
How Many Triangles?
public class TaxCalculator { public static void main(String[] args) { calculateTax(100, 5); } } public static void calculateTax(double amount, double taxRate) { double totalAmount = amount + (amount * taxRate); System.out.println(“The total amount with tax: ” + totalAmount); }
The problem: × You deplete your fuel by contextswitching × You’re not in the flow because of context-switching × Loose-loose: you need more fuel needed, but you have less fuel
When we are tired, we produce worse code × “Developers are cutting corners on quality when fatigued.” (duh)
But We don’t know when to qu x x x it Parole Judges issued fewer paroles when tired and/or hungry Granting parole requires System 2 The Judges didn’t realize they had switched to System 1
Real-life outcome: you run on system one x x x x x Fast Intuitive Automatic Emotional Cheap and Eager x x x x x Slow Analytical Controlled Logical Expensive and Lazy
Which sucks less? Bad code “OK” code
The problem of “ok code” It looks “OK” to us System 1 It looks “OK” to PR review System 1 It looks “OK” to pipelines System 1
Next thing you know: You have an “ok” product
Invest in The goal: Running on System 2 all-day
Time Management Strategies × Time Blocking × Pomodoro Technique × Task Batching
Mindfulness and Cognitive Pra ctices × Mindfulness and Meditation × Reflective Practices × Single-tasking
Workspace and Interruption M an agement × Workspace Organization × Notification Management × Prioritization Techniques
Physical and Mental Well-bein g × Physical Exercise × Breaks and Downtime
And… Developer productivity Engineering!
Developer Productivity Enginee Foster Faster Feedback Collaborate through Effective Tooling Eliminate Toil for Developers Dedicated Organizational Mindset ring Embrace Rigorous Observability for Proactive Improvement Prioritize Automation and Eliminate Bottlenecks Outcomes Over Output
feedback efficiency × × × × IDE: Sub-seconds (I type, it marks it red) Build: Seconds CI: Minutes Production: Hours/Days
Reverse dependency on distance from developers IDE Build CI Feedback Time Faster Slower Distance from Developers Expected Production
Reverse dependency on distance from developers IDE Build CI Production Feedback Time Faster Slower Distance from Developers Expected Real
Two types of feedback x e.g., CI/CD x we never wait for it x results are distracting x e.g., build x we’ll wait for it in the flow x we’ll be pissed off when it’s slow
Reverse dependency on distance from developers Faster IDE Build CI Feedback Time Commit time synchronous asynchronous Slower Distance from Developers Production
“Faster foster feedback” saves Speeding up local build minimizes context switch Less context switch saves mental fuel mental fuel Run on System 2 all-day
How can we engineer less con tex × × × × × t switches? Measure local build times! Avoid building and testing what didn’t change Speed up what can’t be avoided Fight evil flaky tests! Watch your build like a hawk for degradations
What you can do today (for fr ee × × × × × ) Parallel local Local caching Remote caching* Build Scans Win Prizes (a.k.a. speed challenge)
What your company should pa y for × All the books (see shownotes) × Top development hardware × Develocity (or similar)
Learn more and try it today! × × × × Take the Gradle/Maven Speed Challenge Be DPE Agent of Change! Read the DPE Handbook Watch the DPE Summit videos x speaking.jbaru.ch
Embark on an exciting journey into the intersection of psychology, software development, and Developer Productivity Engineering (DPE) as we explore how Nobel laureate Daniel Kahneman’s groundbreaking work on the psychology of judgment and decision-making can optimize your development practices while conserving cognitive resources.
Discover the impact of System 1 and System 2 thinking on the software development process, and learn to strike the perfect balance between “”fast”” intuitive thinking and “”slow”” deliberative reasoning.
We’ll delve into practical DPE strategies for reducing mental fatigue and minimizing context switches, focusing on techniques like build system performance optimization, test parallelization, AI-powered test selection, and developer productivity observability. By leveraging these best practices, you’ll enhance your and your team’s productivity and maintain focus on high-value tasks.
Whether you’re an experienced developer seeking to boost your performance or a curious newcomer eager to learn about the connections between the human mind, software development, and DPE, this talk is for you. Join us for an exhilarating adventure into the fast and slow worlds of coding, and uncover new ways to maximize your cognitive resources.
Video
Resources
The following resources were mentioned during the presentation or are useful additional information.
-
Baruch’s Book DevOps Tools for Java Developers
-
Baruch’s Book Liquid Software
-
Thinking Fast and Slow by Daniel Kahneman
-
Attention and Capacity Limits in Perception: A Cellular Metabolism Account
-
Flow: The Psychology of Optimal Experience by Mihaly Csikszentmihalyi
-
Attention Span by Gloria Mark
-
Characterizing and Predicting Mental Fatigue during Programming Tasks
-
Gradle BuildScan®
-
Gradle Build Cache (Local and Remote)
-
Parallel local tests execution
-
Test Distribution (Parallel cloud test execution)
-
Trends, Reporting and Insights
-
Failure Analytics (Flaky Tests Mitigation)
-
Predictive Test Selection Feature in Develocity
-
Speed Challenge (Win Prizes!)
-
Developer Productivity Engineering (DPE) Handbook
-
DPE Summit
