Designed Stickiness

NCrafts 2016, Paris

Transcript

1. Designed
   Stickiness
   @mathiasverraes
   

   View Slide

2. @mathiasverraes
   verraes.net
   Student of Systems
   Meddler of Models
   Labourer of Legacy
   

   View Slide

3. View Slide

4. Let's talk about
   metaphors that stick
   

   View Slide

5. Great metaphors
   create opportunity
   

   View Slide

6. ( ... even if it takes a while )
   

   View Slide

7. «Breakthrough:
   An opportunity opens up
   to transform your software
   into something
   more expressive and versatile
   than you expected.»1
   1 "Domain-Driven Design", Eric Evans, 2004
   

   View Slide

8. Breakthroughs are often linguistic.
   

   View Slide

9. Language is not a tool like
   metalworking or writing
   It's how our brains are wired2
   2 "The Language Instinct - How the Mind Creates
   Language", Steven Pinker, 1994
   

   View Slide

10. Some language is more sticky
    Advertisers learned this
    a long time ago
    

    View Slide

11. Ceci n'est pas le Ping-Pong.
    

    View Slide

12. Microservices vs SCS-architecture
    

    View Slide

13. The optimistic age of OOP
    Objects as a thinking tool4
    Anthropomorphic objects5
    Objects as projections of the mind
    ...
    5 "Object Design: Roles, Responsibilities, and
    Collaborations", Rebecca Wirfs-Brock & Alan McKean,
    2003
    4 "Object Thinking", David West, 2004
    

    View Slide

14. Mainstream OOP:
    Objects as a way to structure imperative code
    

    View Slide

15. Logger
    {
    log(...)
    {
    ...
    }
    }
    

    View Slide

16. Execution in the
    Kingdom of Nouns6
    6 http://steve-yegge.blogspot.be/2006/03/execution-in-
    kingdom-of-nouns.html
    

    View Slide

17. A healthy obsession
    with language
    

    View Slide

18. View Slide

19. Log
    {
    append(...)
    {
    ...
    }
    }
    

    View Slide

20. Metaphors as objects
    

    View Slide

21. «His people are completely literal.
    Metaphors go over his head.»
    

    View Slide

22. «Nothing goes over my head.
    My reflexes are too fast,
    I would catch it.»
    

    View Slide

23. Example: Data Matching
    Paying money based on usage of content
    Determine ownership based on matches in data
    

    View Slide

24. Data sources:
    Own research by employees
    Off shore data cleaning
    Public wiki-style
    Public but curated
    Private, paid
    Direct submissions from individuals
    Agencies representing owners
    

    View Slide

25. Lots of incentives for fraud
    

    View Slide

26. Is this our Core Domain?
    ✗ It's just technical data imports
    ⬜
    ⬜
    ⬜
    ⬜
    

    View Slide

27. Is this our Core Domain?
    ✗ It's just technical data imports
    ✗ Business is not interested
    ⬜
    ⬜
    ⬜
    

    View Slide

28. Is this our Core Domain?
    ✗ It's just technical data imports
    ✗ Business is not interested
    ✔ Money changing hands
    ⬜
    ⬜
    

    View Slide

29. Is this our Core Domain?
    ✗ It's just technical data imports
    ✗ Business is not interested
    ✔ Money changing hands
    ✔ The code you keep secret
    ⬜
    

    View Slide

30. Is this our Core Domain?
    ✗ It's just technical data imports
    ✗ Business is not interested
    ✔ Money changing hands
    ✔ The code you keep secret
    ✔ Oldest code in the system
    

    View Slide

31. Event Storming
    

    View Slide

32. Temporality
    The quality of data
    changes over time,
    based on who changes it
    

    View Slide

33. Missing concept:
    Matching Data
    =>
    ?
    

    View Slide

34. Missing concept:
    Matching Data
    =>
    Earning Trust
    

    View Slide

35. Trust as a sticky metaphor
    Adopted by business
    

    View Slide

36. Adopted into Ubiquitous Language
    

    View Slide

37. The business started getting
    interested and involved
    

    View Slide

38. What if Trust was a tangible thing
    in our domain model?
    

    View Slide

39. Trust as a Value Object
    

    View Slide

40. Trust can be passed around
    

    View Slide

41. Trust attracts behaviour
    

    View Slide

42. Strategies for changing Trust
    Event-based workflows
    

    View Slide

43. 0 <-> 5 <-> 10
    

    View Slide

44. A Trust Arithmetic
    Invented by the business
    0 <-> 5 <-> 10
    Group
    (closure, associativity, identity, invertibility)
    

    View Slide

45. «Habitable software (...)
    enables people to understand
    its construction and intentions
    and to change it
    comfortably and confidently.»7
    Programmers are not the only
    ones inhabiting our systems
    7 "Patterns of Software", Richard P. Gabriel, 1996
    

    View Slide

46. Example:
    Phone call bill rating
    

    View Slide

47. Price per minute, price after the 60th minute
    Bundles: Credit minutes, lower rates
    Subscriptions: recurring bundles
    Promotions and incentives
    End of month transfers, expiries
    Flexible rating strategies in different markets
    

    View Slide

48. "It's just an algorithm"
    

    View Slide

49. Missing Metaphor:
    Buckets
    

    View Slide

50. View Slide

51. View Slide

52. Mental Model
    ~
    Visual Model
    ~
    Implementation Model
    

    View Slide

53. New opportunity:
    Long lead time to change pricing
    =>
    Lively experimentation with pricing
    

    View Slide

54. System Metaphors (XP)
    are too ambitious
    

    View Slide

55. Metaphors
    are not specifications
    

    View Slide

56. Small, local metaphors
    

    View Slide

57. How to find metaphors?
    It's not magic, it's awareness
    

    View Slide

58. Modelling
    is spending time
    with the problem
    

    View Slide

59. Obsess over language
    

    View Slide

60. Visualise different models
    (structural, temporal, spatial...)
    

    View Slide

61. Grasp the underlying principles of
    the problem and the domain
    

    View Slide

62. «[A paradigm change]
    can happen in a millisecond.
    All it takes is a click in the mind,
    a falling of scales from the eyes,
    a new way of seeing.»8
    8 "Thinking in Systems", Donella H. Meadows, 2008
    

    View Slide

63. Thank you —
    verraes.net
    @mathiasverraes
    verraes.net/workshops
    dddeurope.com
    

    View Slide