7 Years of DDD: Tackling Complexity in Marketing Systems

Turns out Domain-Driven Design works not only for cargo shipping, but for marketing systems as well. In this session I’d like to share the story of Plexop - a large-scale marketing system that spans over a dozen of different business domains: from optimizing advertising spaces, to managing sales agents’ commissions. Plexop had to be implemented with tight resources, and even tighter time to market. That’s why we embraced Domain-Driven Design from day one, and boy did it pay out. I’ll show how DDD allowed us deliver Plexop on time and on budget: what worked, what didn’t, what we had to learn ourselves, and the prices we paid when tried to cut corners.

Transcript

1. 7 YEARS OF DDD:
   TACKLING
   COMPLEXITY

   IN LARGE SCALE
   MARKETING SYSTEMS
   

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2. Vladik Khononov
   IAF Malam Team MSN-IL Cellcom Internovus
   Twitter: @vladikk

   

   Blog: vladikk.com
   

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3. Vladik Khononov
   IAF Malam Team MSN-IL Cellcom Internovus
   Twitter: @vladikk

   

   Blog: vladikk.com
   

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4. AGENDA
   

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5. PART 1

   5 BOUNDED
   CONTEXTS
   PART 2
   PRACTICAL
   ADVICE
   

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7. YAY!!!
   

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8. Your Product Marketing

   Strategy
   Creatives Campaigns Sales

   Agents
   Optimization
   Profits
   

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9. THE FIRST
   BOUNDED CONTEXT
   01
   

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10. VER 1.0
    Media Buying
    Creatives Catalog
    Campaign Management
    

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13. Very nice!
    

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14. Aggregates everywhere!!!
    

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15. Aggregates everywhere!!!
    Creative
    Agency
    Advertiser
    Publisher
    Website
    Placement
    Ad Zone
    Ad Type
    Target Market
    Group
    Zone Type
    Funnel
    Contract
    Budget Unit
    Campaign
    

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16. The Bounded Context
    Creative
    Agency
    Advertiser
    Publisher
    Website
    Placement
    Ad Zone
    Ad Type
    Target Market
    Group
    Zone Type
    Funnel
    Contract
    Budget Unit
    Audience
    

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17. Domain Model
    Service / Application Layer
    Presentation
    Infrastructure
    Anemic!
    Behaviour
    

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18. Imperfect architecture
    “QA is for cowards”
    BUT IT WORKED!
    

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19. UBIQUITOUS LANGUAGE
    

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20. Domain Expert
    Software Developer
    Has no experience in online marketing
    Nice people!
    

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21. Smooth communication
    Strong grasp of the business domain
    Working software
    Aggressive time to market
    

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22. Ubiquitous Language
    Anemic Domain Model
    

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23. Leads Sales Agents
    Ads
    

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24. Leads CRM Categorize Desk
    Desk
    Desk
    Sales Agents
    Sales Agents
    Sales Agents
    Clients’ Systems
    

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26. Lead qualification
    Agent qualification
    Agents’ commissions
    

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27. THE CRM
    BOUNDED CONTEXT
    02
    

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28. Ubiquitous Language
    Anemic Domain Model
    

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29. Creative
    Agency
    Publisher
    Website
    Advertiser
    Ad Zone
    Ad Type
    Target Market
    Group
    Zone Type
    Funnel
    Contract
    Budget Unit
    Audience
    Group
    Desk
    Qualification
    Assessment
    Organization Unit
    Assignment
    Rank
    Message
    On-site Activity
    Placement Visit Brand
    Marketing Lead
    CRM Lead
    Marketing Campaign CRM Campaign
    

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30. Domain Expert
    Software Developer
    …. Lead ….
    …. Campaign…
    

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33. BOUNDED CONTEXTS
    PROTECT THE LANGUAGE
    AGGREGATES PROTECT
    CONSISTENCY OF DATA
    

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34. Creative
    Agency
    Publisher
    Website
    Advertiser
    Ad Zone
    Ad Type
    Target Market
    Group
    Zone Type
    Funnel
    Contract
    Budget Unit
    Audience
    Group
    Desk
    Qualification
    Assessment
    Organization Unit
    Assignment
    Rank
    Message
    On-site Activity
    Placement Visit Brand
    Marketing Lead
    CRM Lead
    Marketing Campaign CRM Campaign
    

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35. Creative
    Agency
    Publisher
    Website
    Advertiser
    Ad Zone
    Ad Type
    Target Market
    Group
    Zone Type
    Funnel
    Contract
    Budget Unit
    Audience
    Placement Visit
    Lead
    Campaign
    Marketing
    Group
    Desk
    Qualification
    Assessment
    Organization Unit
    Assignment
    Rank
    Message
    On-site Activity
    Brand
    Lead
    Campaign
    CRM
    

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36. Aggregates will:

    • Protect transactional boundaries

    • Encompass business logic and invariants
    Domain
    Service / Application Layer
    Presentation
    Infrastructure
    

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37. Aggregates will:

    • Protect transactional boundaries

    • Encompass business logic and invariants
    Domain
    Service / Application Layer
    Presentation
    Infrastructure
    Domain
    Service / Application Layer
    

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41. Stored
    procedures???
    

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42. Group
    Desk
    Qualification
    Assessment
    Organization Unit
    Assignment
    Rank
    Message
    On-site Activity
    Brand
    Lead
    Campaign
    Lead
    

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43. L e a d
    CRM Team DBA Team
    

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45. Inconsistent models
    No shared understanding
    Duplication of knowledge
    Went out of sync quickly
    NIGHTMARE
    

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46. Wasn’t delivered on time
    Production issues
    Data corruption
    Thrown away and reimplemented
    

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47. Ubiquitous Language
    Domain Model
    Bounded Contexts
    Protect w/ Implement as
    

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48. Ubiquitous Language
    Domain Model
    Bounded Contexts
    Protect w/ Implement as
    …Dude, where are Sub-Domains?
    

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49. Not all of a large system will be well designed
    “
    Eric Evans
    

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50. THE CRUNCHERS
    BOUNDED CONTEXT
    03
    

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51. Marketing CRM Analysis
    Customer
    Events
    Marketing CRM
    

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52. Marketing
    CRM
    Analysis
    Customer
    Events
    Event
    Crunchers
    

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53. Competitive advantage? - No
    Off-the-shelve solution? - No
    => Supporting sub-domain
    

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54. Layered Architecture
    Transaction Script
    Worked
    …. for a while
    

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55. Customer
    Events
    Event
    Crunchers
    Marketing
    CRM
    Analysis
    Flag Flag
    Calculated fields
    

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57. Marketing
    CRM
    Analysis
    Customer
    Events
    Event
    Crunchers
    

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58. Customer
    Events
    Event Crunchers
    (BBOM)
    CRM
    Marketing
    Analysis
    

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59. Customer
    Events
    Event
    Crunchers
    (Event Sourced)
    CRM
    Marketing
    Analysis
    

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60. THE BONUSES
    BOUNDED CONTEXT
    04
    

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61. Sales Commissions Reports
    

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62. Competitive advantage? - No
    Off-the-shelve solution? - No
    => Supporting sub-domain
    

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63. Active Record
    Service / Application Layer
    Presentation
    Infrastructure
    

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64. Sales Commissions Reports
    Let’s try different percentages
    What if the percentage could be a function of
    a price?
    No, what if the percentage is a function of
    number of sales?
    No, no, the percentage will be a function
    both of number of sales and sale amount
    And another upgrade if there are more than Y
    sales per week!
    But we will upgrade the percentage if there
    are more than X sales per month!
    

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65. Active Record
    Service / Application Layer
    Presentation
    Infrastructure
    BIG BALL OF MUD
    

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66. Active Record
    Service / Application Layer
    Presentation
    Infrastructure
    Transaction Script
    Service / Application Layer
    Presentation
    Infrastructure
    Event Crunchers Bonuses
    

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67. Active Record
    Service / Application Layer
    Presentation
    Infrastructure
    Transaction Script
    Service / Application Layer
    Presentation
    Infrastructure
    Event Crunchers Bonuses
    Ubiquitous Language
    

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68. Event Sourced Domain Model
    Service / Application Layer
    Presentation
    Infrastructure
    Event Sourced Domain Model
    Service / Application Layer
    Presentation
    Infrastructure
    Event Crunchers Bonuses
    Ubiquitous Language
    

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69. Ubiquitous Language
    Core
    Bounded Contexts
    Protect by

    decomposing to
    Identify
    Domains
    Domain Model
    Supporting
    Generic
    AR / TS
    Adopt
    Implement as
    

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70. THE MARKETING HUB
    BOUNDED CONTEXT
    05
    

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71. Leads Marketing Hub
    Client
    Client
    Client
    

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72. Competitive advantage? - Yes
    => Core Domain
    

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73. Event Sourced Domain Model
    CQRS
    Microservices
    

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74. Micro

    Service
    Micro

    Service
    Micro

    Service
    Micro

    Service
    

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75. Aggregate
    Aggregate
    Aggregate
    Aggregate
    

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76. Aggregate
    Aggregate
    Aggregate
    Aggregate
    Event
    Sourced

    Aggregate
    

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77. Aggregate
    Aggregate
    Aggregate
    Aggregate
    Event
    Sourced

    Aggregate
    

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78. Event Sourced Domain Model
    CQRS
    Microservices
    

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79. Aggregate
    Aggregate
    Aggregate
    Aggregate
    Event
    Sourced

    Aggregate
    

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80. TECHNICAL
    COMPLEXITY
    BUSINESS
    COMPLEXITY
    >
    

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81. Aggregate
    Aggregate
    Aggregate
    Aggregate
    Event
    Sourced

    Aggregate
    

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82. Marketing
    Bonuses
    U D
    CRM
    U
    D
    Marketing

    Hub
    U U
    D
    D
    Event
    Crunchers
    U
    D
    U D
    

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83. WHAT

    WE HAVE
    L E A R N E D
    

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84. UBIQUITOUS
    LANGUAGE
    01
    

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85. Ubiquitous Language:
    The Core Domain of Domain-Driven Design
    

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86. UBIQUITOUS
    LANGUAGE
    DOCUMENTS
    TESTS
    JIRA
    >
    

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87. Marketing
    Ubiquitous Language
    Business goals achieved
    CRM
    Ubiquitous Language
    Production issues
    Long and painful refactoring
    Event Crunchers
    Ubiquitous Language
    Big ball of mud
    Bonuses
    Ubiquitous Language
    Refactored in time
    

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88. Invest in the Ubiquitous Language early on.
    

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89. Cheap!
    

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90. You don’t need a budget for a Ubiquitous Language
    

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91. DOMAIN
    TYPES
    02
    

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92. Core
    Supporting
    Generic
    

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93. Generic Domain Adopt / Buy
    Supporting Domain Active Record / Transaction Script
    Core Domain Domain Model / Event Sourcing
    

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94. COMPANIES CHANGE, EVOLVE, REINVENT THEMSELVES
    DOMAINS' TYPES CAN CHANGE ACCORDINGLY
    

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95. SUPPORTING ➤ CORE
    • Event Crunchers
    • Bonuses
    SUPPORTING ➤ GENERIC
    • Creative Catalog
    CORE ➤ GENERIC
    • Lead Evaluation System
    CORE ➤ SUPPORTING
    • Marketing Hub
    GENERIC ➤ CORE
    • AWS
    

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96. Generic Domain Adopt / Buy
    Supporting Domain Active Record / Transaction Script
    Core Domain Domain Model / Event Sourcing
    

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97. Generic Domain
    Adopt / Buy
    Supporting Domain
    Active Record / Transaction Script
    Core Domain
    Domain Model / Event Sourcing
    

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98. Less waste
    Dialog with the business
    IMPLEMENTATION DESIGN ➤ DOMAIN TYPE
    

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99. • Questionable competitive edge?
    • Accidental “business” complexity?
    • Unexpected competitive edge?
    BUSINESS COMPLEXITY ≠ DOMAIN TYPE?
    

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100. Generic Domain
     Adopt / Buy
     Supporting Domain
     Active Record / Transaction Script
     Core Domain
     Domain Model / Event Sourcing
     IMPLEMENTATION DESIGN ➤ DOMAIN TYPE
     

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101. IMPLEMENTATION
     STRATEGIES
     03
     

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102. How to Model the Business Logic?
     Transaction Script
     Active Record
     Domain Model
     Event Sourced Domain Model
     

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103. MONEY? DEEP ANALYTICS? AUDIT LOG?
     Event Sourced Domain Model
     COMPLEX BUSINESS LOGIC?
     Domain Model
     COMPLEX DATA STRUCTURES?
     Active Record
     SIMPLE LOGIC, SIMPLE DATA STRUCTURES?
     Transaction Script
     

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104. MAPPING ARCHITECTURAL PATTERNS
     Event Sourced Domain Model ➤ CQRS
     Domain Model ➤ Hexagonal Architecture
     Active Record ➤ Layered Architecture
     Transaction Script ➤ “Keep it simple” Architecture
     

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105. MAPPING ARCHITECTURAL PATTERNS
     Event Sourced Domain Model ➤ CQRS
     Domain Model ➤ Hexagonal Architecture
     Active Record ➤ Layered Architecture
     Transaction Script ➤ “Keep it simple” Architecture
     

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106. Transaction Script
     Active Record
     Domain Model
     Event Sourced Domain Model
     

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107. PAIN?
     BUSINESS CHANGED?
     DOMAIN TYPE CHANGED?
     REVISE IMPLEMENTATION STRATEGY?
     ➤
     

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108. Transaction Script
     Active Record
     Domain Model
     Event Sourced Domain Model
     

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109. CQRS
     04
     

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110. Event Sourcing ➤ CQRS
     

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111. EVENT SOURCING
     A WAY OF MODELING BUSINESS DOMAINS
     CQRS
     ARCHITECTURAL PATTERN FOR REPRESENTING
     THE SAME DATA IN DIFFERENT MODELS
     

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112. Transaction Script
     Active Record
     Domain Model
     } Can benefit from CQRS
     and
     State-Based Projections
     

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113. 05
     BOUNDED
     CONTEXTS
     

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114. Creative
     Agency
     Publisher
     Website
     Advertiser
     Ad Zone
     Ad Type
     Target Market
     Group
     Zone Type
     Funnel
     Contract
     Budget Unit
     Audience
     Placement Visit
     Lead
     Campaign
     Marketing
     Group
     Desk
     Qualification
     Assessment
     Organization Unit
     Assignment
     Rank
     Message
     On-site Activity
     Brand
     Lead
     Campaign
     CRM
     LINGUISTIC BOUNDARIES
     

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115. Bonuses
     Event
     Crunchers
     DOMAIN-BASED BOUNDARIES
     

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116. AGGREGATE-BASED BOUNDARIES
     Aggregate
     Aggregate
     Aggregate
     Aggregate
     

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117. L e a d
     SUICIDAL BOUNDARIES
     

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119. Finding service boundaries is really damn hard…
     There is no flowchart!
     “
     Udi Dahan
     

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120. THERE ARE GOING TO BE MISTAKES
     ACCEPT IT, AND DON’T MAKE FATAL ONES
     

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121. START WITH BIGGER BOUNDARIES
     DECOMPOSE LATER, AS YOU GAIN KNOWLEDGE
     

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122. THE LESS YOU KNOW ABOUT THE DOMAIN -
     THE WIDER THE INITIAL BOUNDARIES ARE
     

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123. Aggregate
     Aggregate
     Aggregate
     Aggregate
     Event
     Sourced

     Aggregate
     

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124. Marketing
     Creative
     Agency
     Publisher
     Website
     Advertiser
     Ad Zone
     Ad Type
     Target Market
     Group
     Zone Type
     Funnel
     Contract
     Budget Unit
     Audience
     Placement Visit
     Lead
     Campaign
     

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125. Campaigns
     Creative
     Ad Type
     Agency
     Publisher
     Website
     Zone Type
     Contract
     Budget Unit
     Impression
     Visit
     Lead
     Advertiser
     Target Market
     Funnel
     Audience
     Placement
     Campaign
     Creative Catalog
     Publishers
     Events
     

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126. START WITH BIGGER BOUNDARIES
     DECOMPOSE AS YOU GAIN DOMAIN KNOWLEDGE
     

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127. 1. Ubiquitous Language is not optional
     2. Domain Types change. Embrace these changes
     3. Learn the ins and outs of the four patterns of modeling business logic
     4. Use CQRS to represent the same data in multiple models
     5. Start with bigger boundaries, and divide as you gain domain knowledge
     

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128. 07
     SUMMARY
     

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129. Ubiquitous Language
     Bounded Contexts
     Protect by

     decomposing to
     Design

     Implementation
     Core
     Supporting
     Generic
     Domain Model
     AR / TS
     Adopt
     Confirm w/

     Business
     

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130. Ubiquitous Language
     Bounded Contexts
     Protect by

     decomposing to
     Design

     Implementation
     Core
     Supporting
     Generic
     Domain Model
     AR / TS
     Adopt
     Confirm w/

     Business
     

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131. Ubiquitous Language
     Bounded Contexts
     Protect by

     decomposing to
     Design

     Implementation
     Core
     Supporting
     Generic
     Domain Model
     AR / TS
     Adopt
     Confirm w/

     Business
     

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132. Ubiquitous Language
     Bounded Contexts
     Protect by

     decomposing to
     Design

     Implementation
     Core
     Supporting
     Generic
     Domain Model
     AR / TS
     Adopt
     Confirm w/

     Business
     

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133. Ubiquitous Language
     Bounded Contexts
     Protect by

     decomposing to
     Design

     Implementation
     Core
     Supporting
     Generic
     Domain Model
     AR / TS
     Adopt
     Confirm w/

     Business
     

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134. Creative
     Agency
     Advertiser
     Publisher
     Website
     Placement
     Ad Zone
     Ad Type
     Target Market
     Group
     Zone Type
     Funnel
     Contract
     Budget Unit
     Campaign
     Aggregates everywhere!!!
     

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135. Ubiquitous Language
     Bounded Contexts
     Protect by

     decomposing to
     Design

     Implementation
     Core
     Supporting
     Generic
     Domain Model
     AR / TS
     Adopt
     Confirm w/

     Business
     Ubiquitous Language Everywhere!!!
     

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136. P.S.
     

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138. QUESTIONS?
     

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139. THANK YOU!
     @vladikk
     http://vladikk.com
     

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