Breeding 10x Developers with Developer Productivity Engineering

A presentation at NYJavaSIG in November 2023 in New York, NY, USA by Brian Demers

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Breeding 10x Developers With Developer Productivity Engineering

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Who is this guy? @BrianDemers | bdemers

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source: Silicon Valley @BrianDemers | bdemers

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VS @BrianDemers | bdemers

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VS @BrianDemers | bdemers

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Developer Productivity Engineering @BrianDemers | bdemers

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Myth Origin (probably) The Coding War Games

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The “best” programmers outperformed the worst by roughly a 10:1 ratio There were some interesting “non-factors”: Language Years of Experience Number of Defects Salary

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What Mattered? ⬢ Paired programmers from the same organization performed at roughly the same level ⬢ The average difference was only 21% between paired participants ⬢ They didn’t work together on the task, but they came from the same organization ⬢ The best organizations performed 11.1x better than the worst “While this productivity differential among programmers is understandable, there is also a 10 to 1 difference in productivity among software organizations.” -Harlan D. Mills, Software Productivity

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The best performers are clustering in some organizations while the worst performers are clustering in others. Some companies are doing a lot worse than others. Something about their environment and corporate culture is failing to attract and keep good people or is making it impossible for even good people to work effectively.

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Average performance of those in the top quarter was 2.6 times better than that of those in the bottom quarter. Though the phrase had not yet been coined, increased productivity came down to developer experience.

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10x Organizations are Manufactured, Not Born

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… But Most Organizations Aren’t Aligned In a study dated April 27, 2022, between Microsoft and the University of Victoria in British Columbia, Developers and Managers were surveyed on their interpretation of the SPACE framework

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When surveyed with the following questions, Developers and Managers answered much differently Developers Managers When thinking about your work, how do you define productivity? When thinking about your team, how do you define productivity? https://arxiv.org/pdf/2111.04302.pdf

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DevOps, 12-Factor, Agile, etc, have still not captured all bottlenecks, friction, and obstacles to throughput Many are hiding in plain sight, in the developer experience itself A 10x organization should think about reducing build and test feedback times, and improving the consistency and reliability of builds

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It’s Time for Developer Productivity Engineering

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Code Code Wait Time for Local Build Debug Build Failure Lunch Code Wait Time for Local Build Sprint Waiting time for CI Build Investigate/Fix Flaky Tests 19

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xkcd.com/303

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Multiple Acceleration Technologies are Best

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Build caching delivers fast build and test feedback cycles

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Build Caching ⬢ Introduced to the Java world by Gradle in 2017 ⬢ Maven has an open source build ⬢ Build caches are complementary to dependency caches, not mutually exclusive: ○ dependencies cache too ⬢ Used by leading technology ○ Can support both user local and remote caching for distributed teams A build cache accelerates building a single source repository companies like Google and Facebook ⬢ A dependency cache caches fully compiled ○ A build cache caches build actions (e.g. Gradle tasks or Maven goals)

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What is a Build Cache? Inputs ● Gradle Tasks ● Maven Goal Executions Outputs When the inputs have not changed, the output can be reused from a previous run.

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Cache Key/Value Calculation The cacheKey for Gradle Tasks/Maven Goals is based on the Inputs: cacheKey(javaCompile) = hash(sourceFiles, jdk version, classpath, compiler args) The cacheEntry contains the output: cacheEntry[cacheKey(javaCompile)] = fileTree(classFiles) For more information, see: https://docs.gradle.org/current/userguide/build_cache.html

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https://reproducible-builds.org/

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Test distribution can make tests even faster

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How it works Autoscaler

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Netflix reduced a 62-minute test cycle time down to just under 5 minutes!

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fi Predictive Test Selection leads to greater ef ciencies

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https://research.facebook.com/publications/predictive-test-selection/

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Conventional Test Selection Approach

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Predictive Test Selection Approach 4% 3% 2% 2% 98% 96%

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Build Scans speeds up troubleshooting

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Build Scan - scans.gradle.com

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Without focus, problems can sneak back in… ⬢ ⬢ Infrastructure changes ○ Binary management ○ Caching ○ CI agents New annotation processors or versions of annotation processors ⬢ Build logic configurations settings ○ Build tool version and plugins ○ Compiler and/or Memory settings ⬢ Code refactoring ⬢ New office locations ⬢ Without observability, it is impossible to have a great and fast developer experience.

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“You can observe a lot by just watching” - Yogi Berra, Catcher and Philosopher

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Performance Insights Are you tracking local build and test times?

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Is the cycle fast enough? Is the cycle as fast as it can possibly be?

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DPE Organizations Track Failure Rates

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Dealing with Flaky Tests The test is flaky. What do you do now? a. Try it again b. Re-run it c. Re-run it again d. Ignore it and approve PR e. All of the above

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DPE Organizations Analyze Flaky Tests

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DPE Will Become Standard Practice Because the World Should Foster Developer Joy

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Questions? Thank you! BrianDemers bdemers Learn more & get free swag

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