The Good Architecture

Transcript

1. The Good
   Architecture
   

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2. Krzysztof Wawer
   Github: wafcio
   Twitter: @wafcio
   

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3. 1. Principles
   
   2. Architectures
   

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4. Principles
   

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5. Principles
   • DRY
   

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6. Principles
   • DRY
   
   • KISS
   

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7. Principles
   • DRY
   
   • KISS
   
   • SOLID
   

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8. Principles
   • DRY
   
   • KISS
   
   • SOLID
   
   • YAGNI
   

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9. DRY
   “Don’t Repeat Yourself”
   Andrew Hunt and David Thomas,
   October 1999,
   The Pragmatic Bookshelf
   

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10. DRY
    extras
    extras_allowed?(shop, invoice, order)
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11. KISS
    “Keep it simple, stupid”
    “Keep it stupid simple”
    U.S. Navy in 1960,
    aircraft engineer Kelly Johnson
    

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12. KISS
    

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13. < = >
    LESS IS MORE
    

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14. SOLID
    • SRP (Single Responsible Principle)
    
    • OCP (Open/Closed Principle)
    
    • LSP (Liskov Substitution Principle)
    
    • ISP (Interface Segregation Principle)
    
    • DIP (Dependency Inversion Principle)
    Robert C. Martin
    (Uncle Bob)
    

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15. SRP
    Single Responsible Principle
    • 2002
    
    • A class should have
    one, and only one,
    reason to change
    http://rubyblog.pro/2017/05/solid-single-responsibility-principle-by-example
    

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16. SRP
    Single Responsible Principle
    

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17. Contexts
    

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18. OCP
    Open/Closed Principle
    • 1996
    
    • You should be able
    to extend a classes
    behavior, without
    modifying it
    http://rubyblog.pro/2017/05/solid-open-closed-principle-by-example
    

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19. LSP
    Liskov Substitution Principle
    • 1987
    
    • Barbara Liskov
    
    • Let Φ(x) be a property provable about objects x of type
    T. Then Φ(y) should be true for objects y of type S
    where S is a subtype of T.
    http://rubyblog.pro/2017/06/solid-liskov-substitution-principle
    

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20. LSP
    Liskov Substitution Principle
    • objects in a program
    should be
    replaceable with
    instances of their
    subtypes without
    altering the
    correctness of that
    program
    http://rubyblog.pro/2017/06/solid-liskov-substitution-principle
    

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21. LSP anti-pattern
    

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22. ISP
    Interface Segregation Principle
    • 1996
    
    • Clients should not
    be forced to depend
    upon interfaces that
    they don't use.
    http://rubyblog.pro/2017/07/solid-interface-segregation-principle
    

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23. DIP
    Dependency Inversion Principle
    • 1996
    
    • High-level modules should
    not depend on low-level
    modules. Both should
    depend on abstractions
    
    • Abstractions should not
    depend on details. Details
    should depend on
    abstractions.
    http://rubyblog.pro/2017/07/solid-dependency-inversion-principle
    

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24. SOLID
    Robert C. Martin
    (Uncle Bob)
    

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25. YAGNI
    You aren't gonna need it
    • principle of extreme
    programming (XP)
    
    • XP co-founder Ron
    Jeffries has written:
    "Always implement
    things when you
    actually need them,
    never when you just
    foresee that you
    need them."
    

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26. Architectures
    

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27. Software Architecture
    Chronicles 2000s
    • 2003 - Domain Driven Design
    
    • 2005 - Ports & Adapters Architecture aka Hexagonal Architecture
    
    • ~2006 - CQRS & ES (Event Sourcing)
    
    • 2008 - Onion Architecture
    
    • 2012 - Clean Architecture
    

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28. Domain Driven Design
    

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29. Domain Driven Design
    

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30. Software Architecture
    Chronicles 2000s
    • 2003 - Domain Driven Design
    
    • 2005 - Ports & Adapters Architecture aka Hexagonal Architecture
    
    • ~2006 - CQRS & ES (Event Sourcing)
    
    • 2008 - Onion Architecture
    
    • 2012 - Clean Architecture
    

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31. Hexagonal Architecture
    

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32. Hexagonal Architecture
    

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33. Hexagonal Architecture
    

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34. Hexagonal Architecture
    

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35. Hexagonal Architecture
    

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36. Hexagonal Architecture
    

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37. Hexagonal Architecture
    

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38. Hexagonal Architecture
    

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39. Hexagonal Architecture
    

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40. Hexagonal Architecture
    

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41. Software Architecture
    Chronicles 2000s
    • 2003 - Domain Driven Design
    
    • 2005 - Ports & Adapters Architecture aka Hexagonal Architecture
    
    • ~2006 - CQRS & ES (Event Sourcing)
    
    • 2008 - Onion Architecture
    
    • 2012 - Clean Architecture
    

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42. CQS
    Command Query Separation
    • devised by Bertrand Meyer during his work on the Eiffel
    programming language
    
    • Queries: Return a result and do not change the observable state
    of the system (are free of side effects)
    
    • Commands: Change the state of a system but do not return a
    value
    

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43. Command Query
    Responsible Segregation
    2006 Greg Young describes CQRS
    

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44. Command Query
    Responsible Segregation
    

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45. Command Query
    Responsible Segregation
    

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46. Software Architecture
    Chronicles 2000s
    • 2002 - SRP (SOLID)
    
    • 2003 - Domain Driven Design
    
    • 2005 - Ports & Adapters Architecture aka Hexagonal Architecture
    
    • ~2006 - CQRS & ES (Event Sourcing)
    
    • 2008 - Onion Architecture
    
    • 2012 - Clean Architecture
    

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47. Event-Driven Architecture
    • Event Notification (Event Bus)
    
    • Event Sourcing (Event Store)
    

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48. Event-Driven Architecture
    

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49. Event Sourcing
    

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50. Software Architecture
    Chronicles 2000s
    • 2002 - SRP (SOLID)
    
    • 2003 - Domain Driven Design
    
    • 2005 - Ports & Adapters Architecture aka Hexagonal Architecture
    
    • ~2006 - CQRS & ES (Event Sourcing)
    
    • 2008 - Onion Architecture
    
    • 2012 - Clean Architecture
    

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51. Onion Architecture
    https://herbertograca.com/2017/09/21/onion-architecture/
    

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52. Software Architecture
    Chronicles 2000s
    • 2002 - SRP (SOLID)
    
    • 2003 - Domain Driven Design
    
    • 2005 - Ports & Adapters Architecture aka Hexagonal Architecture
    
    • ~2006 - CQRS & ES (Event Sourcing)
    
    • 2008 - Onion Architecture
    
    • 2012 - Clean Architecture
    

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53. Clean Architecture
    https://blog.cleancoder.com/uncle-bob/2012/08/13/the-clean-architecture.html
    

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54. No architecture
    

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55. @herbertograca
    • https://herbertograca.com
    
    • The Software Architecture Chronicles
    
    • The Containerization Chronicles
    
    • Domain Driven Design
    
    • Lean Architecture
    
    • Patterns of Enterprise Application Architecture
    
    • Patterns Principles and Practices of Domain-Driven Design
    
    • The mythical man-month
    

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56. Q & A
    

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