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
2. Vladik Khononov IAF Malam Team MSN-IL Cellcom Internovus Twitter: @vladikk
 
 Blog: vladikk.com
3. Vladik Khononov IAF Malam Team MSN-IL Cellcom Internovus Twitter: @vladikk
 
 Blog: vladikk.com
4. AGENDA
5. PART 1
 5 BOUNDED CONTEXTS PART 2 PRACTICAL ADVICE
7. YAY!!!
8. Your Product Marketing
 Strategy Creatives Campaigns Sales
 Agents Optimization Profits
9. THE FIRST BOUNDED CONTEXT 01
10. VER 1.0 Media Buying Creatives Catalog Campaign Management
13. Very nice!
14. Aggregates everywhere!!!
15. Aggregates everywhere!!! Creative Agency Advertiser Publisher Website Placement Ad Zone Ad Type Target Market Group Zone Type Funnel Contract Budget Unit Campaign
16. The Bounded Context Creative Agency Advertiser Publisher Website Placement Ad Zone Ad Type Target Market Group Zone Type Funnel Contract Budget Unit Audience
17. Domain Model Service / Application Layer Presentation Infrastructure Anemic! Behaviour
18. Imperfect architecture “QA is for cowards” BUT IT WORKED!
19. UBIQUITOUS LANGUAGE
20. Domain Expert Software Developer Has no experience in online marketing Nice people!
21. Smooth communication Strong grasp of the business domain Working software Aggressive time to market
22. Ubiquitous Language Anemic Domain Model
23. Leads Sales Agents Ads
24. Leads CRM Categorize Desk Desk Desk Sales Agents Sales Agents Sales Agents Clients’ Systems
26. Lead qualification Agent qualification Agents’ commissions
27. THE CRM BOUNDED CONTEXT 02
28. Ubiquitous Language Anemic Domain Model
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
30. Domain Expert Software Developer …. Lead …. …. Campaign…
33. BOUNDED CONTEXTS PROTECT THE LANGUAGE AGGREGATES PROTECT CONSISTENCY OF DATA
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
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
36. Aggregates will:
 • Protect transactional boundaries
 • Encompass business logic and invariants Domain Service / Application Layer Presentation Infrastructure
37. Aggregates will:
 • Protect transactional boundaries
 • Encompass business logic and invariants Domain Service / Application Layer Presentation Infrastructure Domain Service / Application Layer
41. Stored procedures???
42. Group Desk Qualification Assessment Organization Unit Assignment Rank Message On-site Activity Brand Lead Campaign Lead
43. L e a d CRM Team DBA Team
45. Inconsistent models No shared understanding Duplication of knowledge Went out of sync quickly NIGHTMARE
46. Wasn’t delivered on time Production issues Data corruption Thrown away and reimplemented
47. Ubiquitous Language Domain Model Bounded Contexts Protect w/ Implement as
48. Ubiquitous Language Domain Model Bounded Contexts Protect w/ Implement as …Dude, where are Sub-Domains?
49. Not all of a large system will be well designed “ Eric Evans
50. THE CRUNCHERS BOUNDED CONTEXT 03
51. Marketing CRM Analysis Customer Events Marketing CRM
52. Marketing CRM Analysis Customer Events Event Crunchers
53. Competitive advantage? - No Off-the-shelve solution? - No => Supporting sub-domain
54. Layered Architecture Transaction Script Worked …. for a while
55. Customer Events Event Crunchers Marketing CRM Analysis Flag Flag Calculated fields
57. Marketing CRM Analysis Customer Events Event Crunchers
58. Customer Events Event Crunchers (BBOM) CRM Marketing Analysis
59. Customer Events Event Crunchers (Event Sourced) CRM Marketing Analysis
60. THE BONUSES BOUNDED CONTEXT 04
61. Sales Commissions Reports
62. Competitive advantage? - No Off-the-shelve solution? - No => Supporting sub-domain
63. Active Record Service / Application Layer Presentation Infrastructure
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!
65. Active Record Service / Application Layer Presentation Infrastructure BIG BALL OF MUD
66. Active Record Service / Application Layer Presentation Infrastructure Transaction Script Service / Application Layer Presentation Infrastructure Event Crunchers Bonuses
67. Active Record Service / Application Layer Presentation Infrastructure Transaction Script Service / Application Layer Presentation Infrastructure Event Crunchers Bonuses Ubiquitous Language
68. Event Sourced Domain Model Service / Application Layer Presentation Infrastructure Event Sourced Domain Model Service / Application Layer Presentation Infrastructure Event Crunchers Bonuses Ubiquitous Language
69. Ubiquitous Language Core Bounded Contexts Protect by
 decomposing to Identify Domains Domain Model Supporting Generic AR / TS Adopt Implement as
70. THE MARKETING HUB BOUNDED CONTEXT 05
71. Leads Marketing Hub Client Client Client
72. Competitive advantage? - Yes => Core Domain
73. Event Sourced Domain Model CQRS Microservices
74. Micro
 Service Micro
 Service Micro
 Service Micro
 Service
75. Aggregate Aggregate Aggregate Aggregate
76. Aggregate Aggregate Aggregate Aggregate Event Sourced
 Aggregate
77. Aggregate Aggregate Aggregate Aggregate Event Sourced
 Aggregate
78. Event Sourced Domain Model CQRS Microservices
79. Aggregate Aggregate Aggregate Aggregate Event Sourced
 Aggregate
80. TECHNICAL COMPLEXITY BUSINESS COMPLEXITY >
81. Aggregate Aggregate Aggregate Aggregate Event Sourced
 Aggregate
82. Marketing Bonuses U D CRM U D Marketing
 Hub U U D D Event Crunchers U D U D
83. WHAT
 WE HAVE L E A R N E D
84. UBIQUITOUS LANGUAGE 01
85. Ubiquitous Language: The Core Domain of Domain-Driven Design
86. UBIQUITOUS LANGUAGE DOCUMENTS TESTS JIRA >
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
88. Invest in the Ubiquitous Language early on.
89. Cheap!
90. You don’t need a budget for a Ubiquitous Language
91. DOMAIN TYPES 02
92. Core Supporting Generic
93. Generic Domain Adopt / Buy Supporting Domain Active Record / Transaction Script Core Domain Domain Model / Event Sourcing
94. COMPANIES CHANGE, EVOLVE, REINVENT THEMSELVES DOMAINS' TYPES CAN CHANGE ACCORDINGLY
95. SUPPORTING ➤ CORE • Event Crunchers • Bonuses SUPPORTING ➤ GENERIC • Creative Catalog CORE ➤ GENERIC • Lead Evaluation System CORE ➤ SUPPORTING • Marketing Hub GENERIC ➤ CORE • AWS
96. Generic Domain Adopt / Buy Supporting Domain Active Record / Transaction Script Core Domain Domain Model / Event Sourcing
97. Generic Domain Adopt / Buy Supporting Domain Active Record / Transaction Script Core Domain Domain Model / Event Sourcing
98. Less waste Dialog with the business IMPLEMENTATION DESIGN ➤ DOMAIN TYPE
99. • Questionable competitive edge? • Accidental “business” complexity? • Unexpected competitive edge? BUSINESS COMPLEXITY ≠ DOMAIN TYPE?
100. Generic Domain Adopt / Buy Supporting Domain Active Record / Transaction Script Core Domain Domain Model / Event Sourcing IMPLEMENTATION DESIGN ➤ DOMAIN TYPE
101. IMPLEMENTATION STRATEGIES 03
102. How to Model the Business Logic? Transaction Script Active Record Domain Model Event Sourced Domain Model
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
104. MAPPING ARCHITECTURAL PATTERNS Event Sourced Domain Model ➤ CQRS Domain Model ➤ Hexagonal Architecture Active Record ➤ Layered Architecture Transaction Script ➤ “Keep it simple” Architecture
105. MAPPING ARCHITECTURAL PATTERNS Event Sourced Domain Model ➤ CQRS Domain Model ➤ Hexagonal Architecture Active Record ➤ Layered Architecture Transaction Script ➤ “Keep it simple” Architecture
106. Transaction Script Active Record Domain Model Event Sourced Domain Model
107. PAIN? BUSINESS CHANGED? DOMAIN TYPE CHANGED? REVISE IMPLEMENTATION STRATEGY? ➤
108. Transaction Script Active Record Domain Model Event Sourced Domain Model
109. CQRS 04
110. Event Sourcing ➤ CQRS
111. EVENT SOURCING A WAY OF MODELING BUSINESS DOMAINS CQRS ARCHITECTURAL PATTERN FOR REPRESENTING THE SAME DATA IN DIFFERENT MODELS
112. Transaction Script Active Record Domain Model } Can benefit from CQRS and State-Based Projections
113. 05 BOUNDED CONTEXTS
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
115. Bonuses Event Crunchers DOMAIN-BASED BOUNDARIES
116. AGGREGATE-BASED BOUNDARIES Aggregate Aggregate Aggregate Aggregate
117. L e a d SUICIDAL BOUNDARIES
119. Finding service boundaries is really damn hard… There is no flowchart! “ Udi Dahan
120. THERE ARE GOING TO BE MISTAKES ACCEPT IT, AND DON’T MAKE FATAL ONES
121. START WITH BIGGER BOUNDARIES DECOMPOSE LATER, AS YOU GAIN KNOWLEDGE
122. THE LESS YOU KNOW ABOUT THE DOMAIN - THE WIDER THE INITIAL BOUNDARIES ARE
123. Aggregate Aggregate Aggregate Aggregate Event Sourced
 Aggregate
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
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
126. START WITH BIGGER BOUNDARIES DECOMPOSE AS YOU GAIN DOMAIN KNOWLEDGE
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
128. 07 SUMMARY
129. Ubiquitous Language Bounded Contexts Protect by
 decomposing to Design
 Implementation Core Supporting Generic Domain Model AR / TS Adopt Confirm w/
 Business
130. Ubiquitous Language Bounded Contexts Protect by
 decomposing to Design
 Implementation Core Supporting Generic Domain Model AR / TS Adopt Confirm w/
 Business
131. Ubiquitous Language Bounded Contexts Protect by
 decomposing to Design
 Implementation Core Supporting Generic Domain Model AR / TS Adopt Confirm w/
 Business
132. Ubiquitous Language Bounded Contexts Protect by
 decomposing to Design
 Implementation Core Supporting Generic Domain Model AR / TS Adopt Confirm w/
 Business
133. Ubiquitous Language Bounded Contexts Protect by
 decomposing to Design
 Implementation Core Supporting Generic Domain Model AR / TS Adopt Confirm w/
 Business
134. Creative Agency Advertiser Publisher Website Placement Ad Zone Ad Type Target Market Group Zone Type Funnel Contract Budget Unit Campaign Aggregates everywhere!!!
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!!!
136. P.S.
138. QUESTIONS?
139. THANK YOU! @vladikk http://vladikk.com