Réconcilier architecture logicielle & problématiques métiers : une introduction au Domain Driven Design – Blend Web Mix 2021

Avez-vous déjà vécu le fait qu’un petit changement dans le métier déclenche une apocalypse dans le code du logiciel ? Ce genre de symptômes sont souvent le signe que l’architecture du logiciel et le métier de l’entreprise ne sont plus alignés.
Dans cette conférence nous verrons comment permettre aux développeurs d’exprimer les besoins métiers au sein de l’architecture du logiciel afin d’éviter toute une catégorie de problèmes. Problèmes à l’origine d’effets de bords particulièrement dangereux et qui empêchent une politique de refactoring efficace.
Cette présentation des aspects stratégiques de la conception pilotée par le domaine (Domain Driven Design) n’est pas une présentation technique, elle s’adresse ainsi à la fois aux développeurs mais également à l’ensemble des parties prenantes liées à la conception du logiciel.

Transcript

1. www.lilobase.me The strategies behind DDD @lilobase #BlendWebMix sundayapp.com
2. Let’s start a new project !
3. Sprint Zero
4. Sprint Zero Angular or React ?
5. Sprint Zero Java or C# ? Angular or React ?
6. Sprint Zero Java or C# ? Spring Boot or Quarkus ? Angular or React ?
7. Sprint Zero Java or C# ? Spring Boot or Quarkus ? Kafka or Redis ? Angular or React ?
8. Sprint Zero Java or C# ? Spring Boot or Quarkus ? Kafka or Redis ? Microservices or Monolith ? Angular or React ?
9. Sprint Zero Java or C# ? Spring Boot or Quarkus ? Kafka or Redis ? Microservices or Monolith ? Kubernetes or Nomad ? Angular or React ?
10. Look, at our spring boot application with Kafka deployed on a K8S Cluster Sprint Zero
11. Look, at our spring boot application with Kafka deployed on a K8S Cluster They know nothing about the project’s business domain Sprint Zero
12. Look, at our spring boot application with Kafka deployed on a K8S Cluster They know nothing about the project’s business domain … Sprint Zero
13. Java or C# ? Spring Boot or Quarkus ? Kafka or Redis ? Microservices or Monolith ? Kubernetes or Nomad ? Angular or React ? These issues address only the solution
14. But not the problem What should we do ?
15. But not the problem What should we do ? …
16. Spring Boot or Quarkus ? Kafka or Redis ? Microservices or Monolith ? Kubernetes or Nomad ? Angular or React ? And that's why we are seen as technical expert Java or C# ?
17. solution problem What should we do ? How are we going to do it ?
18. solution problem What should we do ? How are we going to do it ? It is an important discussion to have
19. solution problem What should we do ? How are we going to do it ? It is an important discussion to have But only after we've fi gured out 
 what to do
20. DDD is all about Alignment What should we do ? How are we going to do it ?
21. DDD is all about Alignment What should we do ? How are we going to do it ?
22. DDD is all about Alignment What should we do ? How are we going to do it ?
23. « Donnez un marteau à un enfant, et il trouvera que tout a besoin d'être martelé. » – Abraham Kaplan
24. « On fait passer les besoins de la base de donnée avant ceux des utilisateurs ce qui donne des expériences assez pourries » – @WalterStephanie
25. www.lilobase.me DDD is all about Understanding @lilobase
26. Domains & Subdomains Business Domain discovery THE software
27. Domain Mapping Business Domain Classi fi cation Authoring & Publishing Customer Care Printing & Supply Chain Retail Store
28. Domain Mapping Business Domain Classi fi cation Authoring & Publishing Customer Care Printing & Supply Chain Retail Store You need to acknowledge the fact that you have several domains
29. Domain Mapping Business Domain Classi fi cation Authoring & Publishing Customer Care Printing & Supply Chain Retail Store
30. Domain Mapping Business Domain Classi fi cation Authoring & Publishing Customer Care Printing & Supply Chain Retail Store Only one VP should be angry at a time
31. Domain Mapping Business Domain Classi fi cation Authoring & Publishing Customer Care Printing & Supply Chain Retail Store These are neither Bounded Contexts nor Microservices
32. Domain Mapping Business Domain Classi fi cation Authoring & Publishing Customer Care Printing & Supply Chain Retail Store These are your domains
33. Domain Mapping Business Domain Classi fi cation Authoring & Publishing Customer Care Printing & Supply Chain Online Retail Store Payment processor Catalogue Invoicing
34. Domain Mapping Business Domain Classi fi cation Authoring & Publishing Customer Care Printing & Supply Chain Online Retail Store Payment processor Catalogue Invoicing Your domains contain domains
35. Supporting Subdomain Generic Subdomain Core (sub)Domain Key differentiator Domains & Subdomains Business Domain Classi fi cation
36. Supporting Subdomain Generic Subdomain Core (sub)Domain Key differentiator Domains & Subdomains Business Domain Classi fi cation Critical to the 
 organization’s success
37. Supporting Subdomain Generic Subdomain Core (sub)Domain Key differentiator Domains & Subdomains Business Domain Classi fi cation Essential to the 
 organization’s success Critical to the 
 organization’s success
38. Supporting Subdomain Generic Subdomain Core (sub)Domain Key differentiator Domains & Subdomains Business Domain Classi fi cation Essential to the 
 organization’s success Required for the 
 organization’s success Critical to the 
 organization’s success
39. Domain Mapping Business Domain Classi fi cation Authoring Plateform Publishing & Printing Inventory Management Payment Processor Catalogue Invoicing Shipping Order Processing Proofreading
40. Domains & Subdomains Business Domain Classi fi cation Authoring Plateform Inventory Management Shipping Payment Processor Catalogue Invoicing Order Processing Publishing & Printing Proofreading
41. Domains & Subdomains Business Domain Classi fi cation Authoring Plateform Inventory Management Payment Processor Catalogue Invoicing Shipping Order Processing Publishing & Printing Proofreading
42. Domains & Subdomains Business Domain Classi fi cation Authoring Plateform Inventory Management Payment Processor Catalogue Invoicing Each business context is speci fi c Shipping Order Processing Publishing & Printing Proofreading
43. Authoring Plateform Domains’ Connexion Reveal Business Relationships Inventory Management Shipping Catalogue Invoicing Order Processing Payment Processor Publishing & Printing Proofreading
44. Authoring Plateform Domains’ Connexion Reveal Business Relationships Inventory Management Shipping Catalogue Invoicing Order Processing Payment Processor It can highlight signi fi cant 
 sub-domain Publishing & Printing Proofreading
45. Authoring Plateform Domains’ Connexion Reveal Business Relationships Inventory Management Shipping Catalogue Invoicing Order Processing Payment Processor It can highlight signi fi cant 
 sub-domain Publishing & Printing Proofreading
46. www.lilobase.me DDD is all about Context @lilobase
47. From Problem to Solution Authoring Plateform Publishing & Printing Inventory Management Shipping Payment Processor Catalogue Invoicing Order Processing Proofreading
48. From Problem to Solution Authoring Plateform Publishing & Printing Inventory Management Shipping Payment Processor Catalogue Invoicing Order Processing problem solution Payment processor Invoicing Order Processing Shipping Authoring Plateforme Inventory Management Catalogue Publishing Proofreading Proofreading Inventory E-commerce platform Authoring Publishing
49. Domains & Subdomains Development Strategy Supporting Subdomain Generic Subdomain Core (sub)Domain Key differentiator
50. Domains & Subdomains Development Strategy Supporting Subdomain Generic Subdomain Core (sub)Domain In-House development 
 with Your best teams Key differentiator
51. Domains & Subdomains Development Strategy Supporting Subdomain In-House development with 
 external support if possible Generic Subdomain Core (sub)Domain In-House development 
 with Your best teams Key differentiator
52. Domains & Subdomains Development Strategy Supporting Subdomain In-House development with 
 external support if possible Generic Subdomain Outsourcing is an option Core (sub)Domain In-House development 
 with Your best teams Key differentiator
53. Domains & Subdomains Development Strategy Supporting Subdomain Generic Subdomain Core (sub)Domain Key differentiator
54. Domains & Subdomains Development Strategy Supporting Subdomain Generic Subdomain Core (sub)Domain Custom-made software High Cost & Quality Key differentiator
55. Domains & Subdomains Development Strategy Supporting Subdomain Customized Off The Shelf Software 
 is an option Generic Subdomain Core (sub)Domain Custom-made software High Cost & Quality Key differentiator
56. Domains & Subdomains Development Strategy Supporting Subdomain Customized Off The Shelf Software 
 is an option Generic Subdomain Try to fi nd Off The Shelf solution Cost saving opportunities Core (sub)Domain Custom-made software High Cost & Quality Key differentiator
57. From Problem to Solution Payment processor Invoicing Order Processing Shipping Authoring Plateforme Inventory Management Catalogue Publishing Proofreading Inventory E-commerce platform Authoring Publishing Authoring Plateform Publishing & Printing Inventory Management Shipping Payment Processor Catalogue Invoicing Order Processing Proofreading
58. From Problem to Solution Inventory E-commerce platform Authoring Authoring Plateforme Publishing Catalogue Publishing Proofreading Authoring Plateform Publishing & Printing Inventory Management Shipping Payment Processor Catalogue Invoicing Order Processing Proofreading
59. From Problem to Solution Business Domain & Architecture alignment Inventory E-commerce platform Authoring Authoring Plateforme Publishing Catalogue Publishing Proofreading
60. From Problem to Solution Business Domain & Architecture alignment Inventory E-commerce platform Authoring Authoring Plateforme Publishing Catalogue Publishing Proofreading These are your bounded contexts
61. Inventory E-commerce platform Authoring Publishing « Team assignments are the fi rst draft of the architecture » – Michael Nygard
62. Inventory E-commerce platform Authoring Publishing Align your teams with your bounded context « Team assignments are the fi rst draft of the architecture » – Michael Nygard
63. P Authoring Publishing E-commerce Stripe ShipMonk Shopify Context Mapping Relationship Hierarchy OHS OHS ACL OHS C/S
64. Authoring Publishing E-commerce Specific Architecture style You don’t need one architectural style ES CQRS CRUD ? Stripe ShipMonk Shopify
65. Authoring Publishing E-commerce Specific Architecture style You don’t need one architectural style Beware of the CRUD ES CQRS CRUD ? Stripe ShipMonk Shopify
66. Stripe Still no microservices Bounded Context ≠ Deployment units ShipMonk Authoring Publishing E-commerce Shopify Deployment Unit
67. Deployment Unit Stripe Still no microservices Bounded Context ≠ Deployment units ShipMonk Authoring Publishing E-commerce Shopify Deployment Unit
68. Domains are not immutable Understanding is a never-ending process Stripe ShipMonk Authoring Publishing E-commerce Shopify
69. Domains are not immutable Understanding is a never-ending process Stripe ShipMonk Authoring Publishing E-commerce Shopify Printing
70. www.lilobase.me DDD is all about Boundaries @lilobase
71. Semantic Boundaries Between BC meaning are different Authoring Publishing Book Chapter Chapter
72. Semantic Boundaries Between BC meaning are different Authoring Publishing Book Chapter Chapter What happens if the author revises his book?
73. Semantic Boundaries Between BC meaning are different Authoring Publishing Book Chapter Chapter They are not the same book What happens if the author revises his book?
74. Semantic Boundaries Between BC meaning are different Chapter Author Book Reviews Release Catalogue
75. Semantic Boundaries Between BC meaning are different Chapter This is why you must start by understand strategically your domain Author Book Reviews Release Catalogue
76. Semantic Boundaries Between BC meaning are different Authoring Publishing Book Chapter Chapter Book Chapter Chapter
77. Semantic Boundaries Between BC meaning are different Authoring Publishing Book Chapter Chapter Book Chapter Chapter Inside a Bounded Context, 
 Don’t 
 Repeat 
 Yourself
78. Semantic Boundaries Between BC meaning are different Authoring Publishing Book Chapter Chapter Book Chapter Chapter Inside a Bounded Context, 
 Don’t 
 Repeat 
 Yourself Between Bounded Context, 
 Write 
 Everything 
 Twice
79. Don’t cross them Between BC meaning are different Authoring Publishing Author Reviews Author Book Book Release
80. Don’t cross them Between BC meaning are different Authoring Publishing Author Reviews Author Book Book Release
81. Don’t cross them Between BC meaning are different Authoring Publishing Author Reviews Author Book Book Release Never create relationships between entities from two BC
82. Don’t cross them Between BC meaning are different Authoring Publishing Book Book Release Author Author Reviews
83. Don’t cross them Between BC meaning are different Authoring Publishing Book Book Release Author Author Reviews
84. Don’t cross them Between BC meaning are different Authoring Publishing Book Book Release Author Author Reviews This is exactly the same
85. Don’t cross them Between BC meaning are different Authoring Publishing Book Book Release Author Author Reviews API API
86. Same for Events Between BC meaning are different Authoring Publishing Event 
 Bus Book Book Release Author Author Reviews
87. Same for Events Between BC meaning are different Authoring Publishing Event 
 Bus Book Book Release Author Author Reviews
88. Same for Events Between BC meaning are different Authoring Publishing This is exactly the same Event 
 Bus Book Book Release Author Author Reviews
89. Same for Events Between BC meaning are different Authoring Publishing Event 
 Bus Book Book Release Author Author Reviews Translator Translator
90. Transactional Boundaries Protect your integrity Authoring Book Chapter Chapter Chapter Statistics
91. Transactional Boundaries Protect your integrity Authoring Book Chapter Chapter Chapter Statistics Inside your bounded Context 
 live 
 Entities
92. Transactional Boundaries Protect your integrity Authoring Book Chapter Chapter Chapter Statistics Inside your bounded Context 
 live 
 Entities They are grouped in Aggregates
93. Transactional Boundaries Protect your integrity Book Chapter Chapter Chapter Statistics
94. Transactional Boundaries Protect your integrity Book Chapter Chapter Chapter Statistics Inside an aggregate, Entities 
 share the same lifecycle
95. Transactional Boundaries Protect your integrity Book Chapter Chapter Chapter Statistics They are retrieved and persisted 
 as a whole Inside an aggregate, Entities 
 share the same lifecycle
96. Transactional Boundaries Protect your integrity Book Chapter Chapter Chapter Statistics
97. Transactional Boundaries Protect your integrity Book Chapter Chapter Chapter Statistics All interactions are done through the Aggregate Root
98. Transactional Boundaries Protect your integrity Book Chapter Chapter Chapter Statistics Who ensures the aggregate integrity All interactions are done through the Aggregate Root
99. Transactional Boundaries Protect your integrity Book Chapter Chapter Chapter Statistics Who ensures the aggregate integrity All interactions are done through the Aggregate Root Write a new chapter
100. Transactional Boundaries Protect your integrity Book Chapter Chapter Chapter Statistics
101. Transactional Boundaries Protect your integrity Book Chapter Chapter Chapter Statistics Write a new chapter Chapter
102. Transactional Boundaries Protect your integrity Book Chapter Chapter Chapter Statistics Write a new chapter Chapter
103. Transactional Boundaries Protect your integrity Book Chapter Chapter Chapter Statistics Write a new chapter Chapter Inconsistency
104. Transactional Boundaries Protect your integrity Book Chapter Chapter Chapter Statistics Author
105. Transactional Boundaries Protect your integrity Book Chapter Chapter Chapter Statistics But don’t put to much in it Author
106. Transactional Boundaries Protect your integrity Book Chapter Chapter Chapter Statistics But don’t put to much in it Author What happens if we delete the book ?
107. Transactional Boundaries Protect your integrity Book Chapter Chapter Chapter Statistics But don’t put to much in it Author What happens if we delete the book ? They must share the same lifecycle
108. Transactional Boundaries Protect your integrity Book Chapter Chapter Chapter Statistics Author reference Author Id
109. Designing Boundaries Protect your domain Printing Team Book Chapter Chapter Chapter Release API Publishing Team
110. Designing Boundaries Protect your domain Printing Team We need printing margin Book Chapter Chapter Chapter Release API Publishing Team
111. Designing Boundaries Protect your domain Printing Team We need printing margin Book Chapter Chapter Chapter Release Printing margin API Publishing Team
112. Designing Boundaries Protect your domain Printing Team We need printing margin Book Chapter Chapter Chapter Release We need the colorimetric pro fi le Printing margin API Publishing Team
113. Designing Boundaries Protect your domain Printing Team We need printing margin Book Chapter Chapter Chapter Release We need the colorimetric pro fi le Printing margin Colorimetric pro fi le API Publishing Team
114. Designing Boundaries Protect your domain API We need printing margin Book Chapter Chapter Chapter Release We need the colorimetric pro fi le Printing margin Colorimetric pro fi le Domain Leakage Publishing Team Printing Team
115. Designing Boundaries Protect your domain API We need printing margin Book Chapter Chapter Chapter Release We need the colorimetric pro fi le Printing margin Colorimetric pro fi le Domain Leakage Publishing Team Printing Team
116. Designing Boundaries Protect your domain Publishing Team Printing Team Publishing API Book
117. Designing Boundaries Protect your domain Publishing Team Printing Team Publishing API Book Printing API
118. Designing Boundaries Protect your domain Publishing Team Printing Team Publishing API We need printing margin Book Printing API
119. Designing Boundaries Protect your domain Publishing Team Printing Team Publishing API We need printing margin Book Printing margin Printing API
120. Designing Boundaries Protect your domain Publishing Team Printing Team Publishing API We need printing margin Book We need the colorimetric pro fi le Printing margin Printing API
121. Designing Boundaries Protect your domain Publishing Team Printing Team Publishing API We need printing margin Book We need the colorimetric pro fi le Printing margin Colorimetric pro fi le Printing API
122. Designing Boundaries Protect your domain Publishing Team Printing Team Publishing API We need printing margin Book We need the colorimetric pro fi le Printing margin Colorimetric pro fi le Printing API We discovered the need 
 for an ACL
123. www.lilobase.me DDD is all about Behavior @lilobase
124. CRUD don’t express behavior It blinds you from the business perspective UPDATE address Relocation Mistake correction
125. CRUD don’t express behavior It blinds you from the business perspective UPDATE address Relocation Mistake correction
126. CRUD don’t express behavior It blinds you from the business perspective Relocation Mistake correction
127. Data oriented programming It obfuscates your code – Mathias Verraes $order->setStatus('paid') ; $order->setPaidAmount(120) ; $order->setPaidCurrency('EUR') ; $order->setCustomer($customer);
128. Data oriented programming It obfuscates your code – Mathias Verraes $order->pay() ;
129. Data oriented programming It obfuscates your code $money = new Money(120, new Currency(‘EUR')) ; $order->setPaidMoney($money); – Mathias Verraes $order->pay() ;
130. Data oriented programming It obfuscates your code $money = new Money(120, new Currency(‘EUR')) ; $order->pay($customer, $money); – Mathias Verraes
131. Data oriented programming It obfuscates your code $money = new Money(120, new Currency(‘EUR')) ; $order->pay($customer, $money); – Mathias Verraes $customer->pay($order, $money) ;
132. Data oriented programming It obfuscates your code – Mathias Verraes $customer->pay($order, $money) ; $order->setStatus('paid') ; $order->setPaidAmount(120) ; $order->setPaidCurrency('EUR') ; $order->setCustomer($customer);
133. Task Based UI Your customer’s need isn’t to fi ll out forms
134. Users don’t need to fill out forms
135. Users don’t need to fill out forms
136. www.lilobase.me DDD is all about Compassion @lilobase
137. A A A Ubiquitous language Stakeholders & Team Alignement Dev Domain 
 Expert Dev
138. A A A Ubiquitous language Stakeholders & Team Alignement Dev Domain 
 Expert Dev
139. A A A Ubiquitous language Stakeholders & Team Alignement Dev Domain 
 Expert Dev
140. A A A Ubiquitous language Stakeholders & Team Alignement Dev Domain 
 Expert Dev
141. A A A not « just » a glossary Ubiquitous language Stakeholders & Team Alignement Dev Domain 
 Expert Dev
142. A A A not « just » a glossary Ubiquitous language Stakeholders & Team Alignement Dev Domain 
 Expert Dev
143. Ubiquitous language Each BC has its own Authoring Publishing A A
144. Ubiquitous language Each BC has its own Authoring Publishing A A A A
145. Ubiquitous language Each BC has its own Authoring Publishing A A A A
146. Ubiquitous language Each BC has its own Authoring Publishing A A A A
147. Ubiquitous language Each BC has its own Authoring Publishing A A A A It is a common cause of miscommunication
148. Pair Programing The best way to share a domain understanding Dev
149. Pair Programing The best way to share a domain understanding Dev Domain 
 Expert
150. Know your users They might not be who you think they are Dev Domain 
 Expert Product 
 Owner Customer User
151. Know your users They might not be who you think they are Dev Domain 
 Expert Product 
 Owner Customer User He has the last word regarding domain implementation
152. Know your users They might not be who you think they are Dev Domain 
 Expert Product 
 Owner Customer User Prioritize development & formalize users’ feedback
153. Know your users They might not be who you think they are Dev Domain 
 Expert Product 
 Owner Customer User Power of Life and Death over the project
154. Know your users They might not be who you think they are Dev Domain 
 Expert Product 
 Owner Customer User Too often forgotten
155. Know your users They might not be who you think they are Dev Domain 
 Expert Product 
 Owner Customer User Maybe you could spend a day per month working with them ?
156. Know your users They might not be who you think they are Dev Domain 
 Expert Product 
 Owner Customer User They design the software speci fi cation
157. Know your users They might not be who you think they are Dev Domain 
 Expert Product 
 Owner Customer User What he understood goes 
 into production
158. “A loosely coupled software architecture and org structure to match” is a key predictor of: — Michael Plöd (@bitboss)
159. “A loosely coupled software architecture and org structure to match” is a key predictor of: • Continuous Delivery Performance — Michael Plöd (@bitboss)
160. “A loosely coupled software architecture and org structure to match” is a key predictor of: • Continuous Delivery Performance • Ability to scale organization and increase performance linearly — Michael Plöd (@bitboss)
161. “A loosely coupled software architecture and org structure to match” is a key predictor of: • Continuous Delivery Performance • Ability to scale organization and increase performance linearly This is what DDD is All About ! — Michael Plöd (@bitboss)
162. www.lilobase.me @lilobase https://roti.express/r/gstywv sundayapp.com