Modernizing through evolution not revolution

Due to unavoidable compromises, over time, projects inevitably lean more towards growth and depth than general modernization, to the point that they become difficult to maintain. So, what happens when the bugs add up and the monster emerges? Refactor? Rewrite from scratch? The speaker shall expand and explain what to look out for, from both a technical and business perspective.

Presented at CFSummit 2022, Las Vegas, US

Transcript

1. MODERNIZING THROUGH
   EVOLUTION NOT REVOLUTION
   
   
   GUUST NIEUWENHUIS
   

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2. ABOUT ME
   Guust Nieuwenhuis
   Managing Partner @ We Are North
   
   
   Full Stack Web Wizard
   
   
   Masa CMS
   
   
   Born in The Netherlands
   
   
   Living in Belgium
   
   
   Soccer coach
   
   
   Mountainbiker
   

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3. MODERNIZING THROUGH
   EVOLUTION NOT REVOLUTION
   
   
   GUUST NIEUWENHUIS
   

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4. 10 YEARS
   Average software lifetime
   

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5. Spaghetti code
   
   
   Outdated framework
   
   
   Unsupported libraries
   
   
   Deprecated integrations
   
   
   No tests
   
   
   Not documented
   
   
   Difficult to develop
   
   
   Hard to maintain
   
   
   

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6. What’s next?
   

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8. Flights booking engine
   
   
   Performance issues
   
   
   Decided to rewrite from the ground up
   
   
   Kept adding new functionality to the “old” engine
   
   
   Development of the “new” engine trying to catch up
   
   
   Financial disaster
   

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9. REWRITE CODE FROM SCRATCH
   IS THE SINGLE WORST STRATEGIC
   MISTAKE THAT ANY SOFTWARE
   COMPANY CAN MAKE
   Joel Spolsky
   

   Co-founder Trello and Stack Over
   fl
   ow
   

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10. A feeling isn’t sufficient
    
    
    Rewrite delays the release of the project
    
    
    More bugs and less functionality
    
    
    Expensive
    
    
    No guaranteed success
    
    
    

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11. So, what’s next?
    

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13. 12+ years old web application
    
    
    New separate API for mobile app
    
    
    New report builder module
    
    
    Integrated new module in old application
    
    
    Sharing the database
    
    
    Feature flags
    

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14. 12+ years old web application
    
    
    New separate API for mobile app
    
    
    New report builder module
    
    
    Integrated new module in old
    application
    
    
    Sharing the database
    
    
    Feature flags
    

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15. 12+ years old web application
    
    
    New separate API for mobile app
    
    
    New report builder module
    
    
    Integrated new module in old
    application
    
    
    Sharing the database
    
    
    Feature flags
    

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17. 25+ years old client-server app
    
    
    Need to move to “The Cloud”
    
    
    New module developed
    
    
    Domain Driven Design
    
    
    Microservices architecture
    
    
    Events between “old” and “new”
    

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18. 25+ years old client-server app
    
    
    Need to move to “The Cloud”
    
    
    New module developed
    
    
    Domain Driven Design
    
    
    Microservices architecture
    
    
    Events between “old” and “new”
    

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19. How?
    

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20. 1. Case
    

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21. 1. Case
    
    
    2. Boundary
    

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22. 1. Case
    
    
    2. Boundary
    
    
    3. Strategy
    

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23. 1. Case
    
    
    2. Boundary
    
    
    3. Strategy
    
    
    Bubble Context
    

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24. 1. Case
    
    
    2. Boundary
    
    
    3. Strategy
    
    
    Bubble Context
    

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25. 1. Case
    
    
    2. Boundary
    
    
    3. Strategy
    
    
    Bubble Context
    
    
    Anticorruption layer (ACL)
    

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26. 1. Case
    
    
    2. Boundary
    
    
    3. Strategy
    
    
    Bubble Context
    
    
    ACL Synchronisation
    

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27. 1. Case
    
    
    2. Boundary
    
    
    3. Strategy
    
    
    Event queue
    

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28. SAME HABITS, SAME MISTAKES!
    

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29. WANT TO READ MORE?
    Domain Driven Design
    Bounded Context
    Strangler Fig Pattern
    Anti Corruption Layer
    Eric Evans
    Martin Fowler
    Anti Patterns
    Event Driven Architecture
    Microservices
    Feature Flags
    

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30. ONE MORE THING
    Steve Jobs
    
    
    Co-founder of Apple, Next and Pixar
    

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32. 3 applications
    
    
    Overlapping functionality
    
    
    Consolidate applications
    
    
    Minimum viable product (MVP)
    
    
    Won’t copy all functionality
    
    
    Business case drives rewrite!
    

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33. 3 applicaties
    
    
    Overlapping functionality
    
    
    Consolidate applications
    
    
    Minimum viable product (MVP)
    
    
    Won’t copy all functionality
    
    
    Business case drives rewrite!
    

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34. MODERNIZING THROUGH
    EVOLUTION NOT REVOLUTION
    
    
    guust@wearenorth.eu
    
    
    https://www.linkedin.com/in/guustnieuwenhuis
    

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