DomainDriven Design Overview

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1. The Conventional Approach

1.1. Software development process ? Problem Discussion Design Code Run

1.2. Responsibilities defined by conventional Devs ? Problem Discussion Design Code Run

1.3. Knowledge distribution [IESAB]

1.4. Limits of scalability

1.5. Accidential Complexity Utils Libs Model UI Components Persistence 1 Persistence 3 Model Feature

1.6. Wrong Vision

1.7.1 Misunderstanding „Apache“

1.7.2 Misunderstanding “It’s developers’ (mis)understanding, not expert knowledge that gets released in production.” - Alberto Brandolini -

1.8. Upfront Design [PPPDDD]

1.9. Communication Structures “Organizations which design systems ... are constrained to produce designs which are copies of the communication structures of these organizations.” - Conway’s Law -

2. Beyond the Conventional Approach

2.1.1. Responsibilities defined by DevOps “You build it, you run it” - Werner Vogels -

2.1.2. Responsibilities defined by DevOps ? Problem Discussion Design Code Run

3. DomainDriven Design to the rescue

3.1. Responsibilities defined by DomainDriven Design ? Problem Discussion Design Code Run

3.2. History of literature 2003 2013 2016 2015 2019

3.3. Elements of DomainDriven Design • Strategic Design adresses a top-down approach by breaking complexity down from domains to subdomain and further down to Bounded Contexts. • Tactical Design, on the other hand, can be used for bottum-up analysis and design since it has a focus in finer grained building blocks like Value Objects, Entities or Aggregates. [HODDDBE]

3.4. Model Exploration Whirlpool

4. Strategic Design

4.1.1. Problem Space ? Problem Discussion Design Code Run Problem Space

4.1.2. Problem Space Context of wider business Problem Domain

4.2. Ubiquitous Language [AODDDBSM]

4.3. Knowledge Crunching [PPPDDD]

4.4. Domain Subdomain Subdomain Subdomain Subdomain Subdomain

4.5. Focus on the Core Domain [AODDDBSM]

4.6. Subdomains Core Domain Generic Domain Support Domain Support Domain Generic Domain

5. Techniques for Knowledge Crunching

4.1. Event Storming [IESAB]

5.2. Domain Storytelling [DSSHHS]

5.3. User Story Mapping [USMJP]

5.4. Example Mapping [EMMW]

5.5. Behavior-Driven Design [BDDWiki]

5.6. Impact Mapping [IMTK]

5.7. Wardly Map [WMSW]

5.8. Business Model Canvas [15YDDD]

6. Tactical Design

6.1. Solution Space ? Problem Discussion Design Code Run Solution Space

6.2. Solution Space [PPPDDD]

6.3.1. Domain Model [AODDDBSM]

6.3.2. Domain Model „All models are wrong, but some are useful“ - George E. P. Box -

6.4. Bounded Context

6.5. Context Mapping • Open-host Service • Published Language • Conformist • Customer / Supplier • Anticorruption Layer • Shared Kernel • Big Ball of Mud • Partnership • Seperate Ways

6.6. Context Map [HODDDBE]

6.7. Building Blocks [HODDDBE]

6.8. Model Exploration Whirlpool [PPPDDD]

6.9. History of concepts 2003 2005 Event Sourcing 2010 Command
 Query
 Responsibility
 Segregation Micro Service Self
 Contained
 System Distributed
 DDD 2015 2011 Workshop of Software
 Architects 2005 Hexagonal Architecture DomainDriven
 Design

6.10. Self-Contained Systems [SCSWEB]

6.11. Hexagonal Architecture

6.12. Scalability with Bounded Contexts

6.13. Organisational Structure „In other words, your application‘s architecture mirrors the structure of the organization that developed it. It is important, therefore, to apply Conway‘s Law in reverse and design your organisation so that its structure mirrors your microservice architecture.“ - Chris Richardson -

7. Beyond DomainDriven Design

7.1.1. Responsibilities defined by DDD & DevOps "You design it, you build it, 
 and then you run it“ - Michael Plöd -

7.1.2. Responsibilities defined by DDD & DevOps ? Problem Discussion Design Code Run

End of presentation

Thank you! • Markus Hanses • @markushanses • hanses.markus@gmail.com

Sources 1 • [DLWEB], Documentation, https://domainlanguage.com/ddd/whirlpool/ • [MFESWEB], Event Sourcing, https://martinfowler.com/eaaDev/EventSourcing.html • [MIROWEB], Miro Application, https://miro.com • [AKWEB], Presentation, https://www.slideshare.net/aslamkhn/experiments-in-reasoning-227676025 • [GYCQRSWEB], CQRS, https://cqrs.files.wordpress.com/2010/11/cqrs_documents.pdf • [ISAWEB], ISA Principles, https://isa-principles.org/ • [DDDWiki], DomainDriven Design, https://en.wikipedia.org/wiki/Domain-driven_design • [SCSWEB], Self Contained System, http://scs-architecture.org/ • [IESAB], Introducing EventStorming, Alberto Brandolini, leanpub.com • [DSSHHS], Domain Storytelling, Stefan Hofer, Henning Schwentner, leanpub.com • [USMJP], User Story Mapping, https://www.jpattonassociates.com/user-story-mapping/ • [EMMW], Example Mapping, https://cucumber.io/blog/bdd/example-mapping-introduction/ • [IMTK], Impact Mapping, https://blog-de.akquinet.de/2016/12/14/von-der-loesung-zum-problem- impact-mapping-mal-anders-herum/ • [WMSW], Wardly Map,https://medium.com/wardleymaps • [BDDWiki], Behavior-Driven Design, https://en.wikipedia.org/wiki/Behavior-driven_development • [HAWiki], Hexagonal Architecture, https://en.wikipedia.org/wiki/Hexagonal_architecture_(software) • [HAAC], Hexagonal Architecture, Alistair Cockburn, https://web.archive.org/web/20180822100852/ http://alistair.cockburn.us/Hexagonal+architecture • [15YDDD], DDD Europe, Domain-Driven Design: The First 15 Years, https://leanpub.com/ ddd_first_15_years

Sources 2 • [AODDDBSM] The Anatomy of Domain-Driven Design - Booklet, Samual Knight & Scott Millett, https://leanpub.com/theanatomyofdomain-drivendesign • [PPPDDD], „Patterns, Principles, and Practices of Domain-Driven Design“, ISBN: 978-1-118-71470-6 • [HODDDBE], Hands On Domain-driven Design by example, Michael Plöd, https:// leanpub.com/ddd-by-example