XP Days Ukraine -- A Crystal Ball to Prioritize Technical Debt

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@AdamTornhill

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“Like a ﬁnancial debt, the technical debt incurs interest payments, which come in the form of the extra effort that we have to do in future development” Questioning Technical Debt https://martinfowler.com/bliki/TechnicalDebt.html @AdamTornhill

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Interest Rate Is A Function Of Time http://i.imgur.com/a8Xo4Hp.png @AdamTornhill

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All Technical Debt Isn’t Equal @AdamTornhill

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@AdamTornhill Most Technical Debt Isn’t Technical

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There’s A Strong Link Between Technical Debt And The Organisation @AdamTornhill

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Wish List: Information to Prioritize Technical Debt @AdamTornhill Where’s the Highest Interest Rate? Does the Architecture Support the way our System Evolves? Any Productivity Bottlenecks for Inter-Team Coordination?

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Collective Intelligence @AdamTornhill Uncover Evolutionary Patterns In A System Commit: b557ca5 Date: 2016-02-12 Author: Kevin Flynn Fix behavior of StartsWithPrefix 8 27 src/Mvc.Abstractions/ModelBinding/ModelStateDictionary.cs 1 10 src/Mvc.Core/ControllerBase.cs 1 1 src/Mvc.Core/Internal/ElementalValueProvider.cs 1 39 src/Mvc.Core/Internal/PrefixContainer.cs Commit: fd6d28d Date 2016-02-10 Author: Professor Falken Make AddController not overwrite existing IControllerTypeProvider 8 1 src/Core/Internal/ControllersAsServices.cs 48 0 test/Core.Test/Internal/ControllerAsServicesTest.cs 13 0 test/Mvc.FunctionalTests/ControllerFromServicesTests.cs Commit: 910f013 Date :2016-02-05 Author Lisbeth Salander Fixes #4050: Throw an exception when media types are empty. 20 1 src/Mvc.Core/Formatters/InputFormatter.cs Social Information A Time Dimension

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Hotspots Where’s The Highest Interest Rate?

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Hotspots - A Tool To Prioritize @AdamTornhill

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Code Complexity Code Change Frequency Hotspot @AdamTornhill

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Hotspots - A Tool To Prioritize Hotspots Hotspots

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All Code is Equal …but some Code is more equal than others* * Sorry, George Orwell

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Why Hotspots Work 1 Year in Roslyn (C#, VB) 6 Years of Erlang 12 Years of Ruby on Rails Each ﬁle in the system Change Frequency Reference: Your Code as a Crime Scene, ISBN:1680500384 Prioritize improvements here! Ignore the long tail

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Hotspots

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Case Study: @AdamTornhill

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gc.cpp @AdamTornhill

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File Level Hotspots Function Level Hotspots X Ray Recommended functions to improve. Hotspots X-Ray

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Normalization of Deviance @AdamTornhill

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Supervise your Complexity Trends @AdamTornhill Warning Sign! Refactoring Increases again

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Hotspots Summary Hotspots find the code with the highest interest rate. Hotspots work because all code isn’t equal. Supervise the Complexity Trend of your Hotspots.

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Evaluate Your Architectural Patterns Does the Architecture Support the way our System Evolves?

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Code is Auto-Destructive Art @AdamTornhill

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DRM Shared DRM/AMD … Specify Your Logical Components @AdamTornhill

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Identify Hotspots on a (Micro)Service Level @AdamTornhill

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FuelInjector Temporal Coupling Diagnostics Combustion Commit #1 Commit #2 Commit #3 Time Read More: http://www.empear.com/blog/software-revolution-part3/ @AdamTornhill

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Model Controller View Services ORM Repository SQL Layers: A Separation of Concerns General Observation: 30-70 % of all commits touch multiple layers @AdamTornhill Change Coupling

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Supervise The Change Coupling Between Services @AdamTornhill Temporal Coupling (potentially across repository boundaries)

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The Microservices Shotgun Surgery Pattern @AdamTornhill

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Tools Evolution Radar http://reveal.inf.usi.ch/web/dambros/tools/evoradar.php CodeScene: https://codescene.io/ Moose Platform: open source platform http://www.moosetechnology.org/ Code Maat: open source, text-only (GPL) https://github.com/adamtornhill/code-maat

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Architecture Summary Identify your Architectural Hotspots. Know your System’s Tipping Point. Use Temporal Coupling to Evaluate your Architecture.

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Meet The Social Side of Your Code Any Productivity Bottlenecks for inter-team coordination?

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Process Loss Process Loss The Potential Productivity Individual Contributions Real Productivity Team Work @AdamTornhill

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Diffusion of Responsibility

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Fractal Value: M. D’Ambros, M. Lanza, and H Gall. Fractal Figures: Visualizing Development Effort for CVS Entities. Inter-Team Overlap Fractal Value 0 ~1.0 Views Integration Tasks Backup Tests Measure Team Coordination Excess Parallel Work The Diffusion of Responsibility

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Measuring Conway’s Law Architectural Pattern: Package by Feature Views Features @AdamTornhill Front-End Team Export Team Recommendations Team Ads Team Calculations Team Backup Team

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Team Team Team Team Team Team Team Team Team Team Team Team The Perils of Feature Teams @AdamTornhill

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Align Your Architecture and your Organisation @AdamTornhill

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Make Decisions Influenced By Data @AdamTornhill

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@AdamTornhill Blog on Behavioral Code Analysis http://www.empear.com/blog/ Read The Books: Your Code As A Crime Scene https://pragprog.com/book/atcrime/your-code-as-a-crime-scene Software Design X-Rays (October 2017) https://pragprog.com/book/atevol/software-design-x-rays Run the Analyses in CodeScene: https://codescene.io/ adam.tornhill@empear.com