my-ddd-journey

A list of Domain-Driven Design resources that I found interesting on my journey studying DDD.

Books

• Domain-Driven Design Distilled. Vaughn Vernon – 2016.
• Implementing Domain Driven Design - Vaughn Vernon.
• Domain-Driven Design: Tackling Complexity in the Heart of Software - Eric Evans - 2003.
• The Anatomy Of Domain-Driven Design - Booklet https://leanpub.com/theanatomyofdomain-drivendesign
• Designing Autonomous Teams and Services, Nick Tune and Scott Millett - 2017 http://www.oreilly.com/programming/free/designing-autonomous-teams-and-services.csp
• CQRS Documents, Greg Young https://github.com/keyvanakbary/cqrs-documents
• Functional and Reactive Domain Modeling, Debasish Ghosh - 2016.
• Domain Modeling Made Functional: Tackle Software Complexity with Domain-Driven Design and F#, Scott Wlaschin - 2018.
• Strategic Monoliths and Microservices: Driving Innovation Using Purposeful Architecture, Vaughn Vernon, Tomasz Jaskula - 2021.

Online Courses

• Domain-Driven Design Fundamentals by Julie Lerman and Steve Smith (6/2014)
• Domain-Driven Design in Practice, Vladimir Khorikov. (1/2016)
• Domain-Driven Design Distilled, Vaughn Vernon. (3/2017)
• CQRS Tutorial http://cqrs.nu/
• Refactoring from Anemic Domain Model, Vladimir Khorikov * My notes
• CQRS in Practice, Vladimir Khorikov (10/2018) * My notes
• Domain-Driven Design, Javier Ferrer and Rafa Gómez (2019)
• DDD and EF Core: Preserving Encapsulation, Vladimir Khorikov. (4/3/2020)
• Software Architecture: Domain-Driven Design, Allen Holub (18/09/2019)

Podcasts

• Interview Eric Evans, SE-Radio (09/03/2006) http://www.se-radio.net/2006/03/episode-8-interview-eric-evans/
• Eric Evans on Domain-Driven Design at 10 Years, SE-Radio (13/05/2015) http://www.se-radio.net/2015/05/se-radio-episode-226-eric-evans-on-domain-driven-design-at-10-years/
• Reactive Programming with the Actor Model, Vaughn Vernon, SE-Radio (12/02/2016) http://www.se-radio.net/2016/02/se-radio-episode-249-vaughn-vernon-on-reactive-programming-with-the-actor-model/
• Being The Worst. Audio apprenticeships for the aspiring software craftsman. Currently exploring DDD, Event Sourcing, CQRS, distributed systems, etc. http://www.beingtheworst.com/
• Domain Driven Design and Micro Services, Vaughn Vernon. (17/08/208) https://corecursive.com/018-micro-services-and-domain-driven-design-with-vaughn-vernon/
• Domain-Driven Design & Event Storming, Jakub Pilimon (5/12/2018) https://content.pivotal.io/podcasts/domain-driven-design-event-storming-with-jakub-pilimon

Articles

Aggregates

• DDD Decoded - The Aggregate and Aggregate Root Explained, Mike Mogosanu http://blog.sapiensworks.com/post/2016/07/14/DDD-Aggregate-Decoded-1
• Identifying An Aggregate Is Not Object Oriented Design, Mike Mogosanu http://blog.sapiensworks.com/post/2018/01/08/DDD-Aggregate-groups-behaviour-not-data
• Strengthening your domain: Aggregate Construction, Jimmy Bogard (24/02/2010) https://lostechies.com/jimmybogard/2010/02/24/strengthening-your-domain-aggregate-construction/
• Aggregate Roots Should Look After Their Own Events, Mike Mogosanu (22/05/2014) http://blog.sapiensworks.com/post/2014/05/22/Aggregate-Roots-Should-Look-After-Their-Own-Events.aspx.html
• DDD - Persisting Aggregate Roots In A Unit Of Work, Mike Mogosanu (01/05/2013) http://blog.sapiensworks.com/post/2013/05/01/DDD-Persisting-Aggregate-Roots-In-A-Unit-Of-Work.aspx
• Aggregates and RFC 2119, Danil Suits (05/02/2017) http://cascadefaliure.vocumsineratio.com/2017/02/aggregates-and-rfc-2119.html

Entities

• How not to inject services in entities, Jeremie Chassaing (04/03/2009) https://thinkbeforecoding.com/post/2009/03/04/How-not-to-inject-services-in-entities [Explains how Double Dispatch can be the solution when an Entity needs to use a service]
• Entities should look after their own events, Mat McLoughlin http://mat-mcloughlin.net/2014/05/22/entities-should-look-after-their-own-events/
• A Better Way to Project Domain Entities into DTOs, Nick Chamberlain https://buildplease.com/pages/repositories-dto/ [Should the projection from Aggregate(s) to DTO be done inside your Repositories?]

Value Objects

• Value Objects Like a Pro, Nicolò Pignatelli https://hackernoon.com/value-objects-like-a-pro-f1bfc1548c72
• Domain-Driven Design: The Identifier Type Pattern, Gara Mohamed https://medium.com/@gara.mohamed/domain-driven-design-the-identifier-type-pattern-d86fd3c128b3 [... Primitive Identifier vs Type Identifier and Value Objects in TypeScript]

Domain Services

• Services in Domain-Driven Design, Jimmy Bogard https://lostechies.com/jimmybogard/2008/08/21/services-in-domain-driven-design/
• Strengthening your domain: The double dispatch pattern, Jimmy Bogard https://lostechies.com/jimmybogard/2010/03/30/strengthening-your-domain-the-double-dispatch-pattern/
• And Then This Happened, Vaughn Vernon (24/11/2018) https://kalele.io/cqrs/and-then-this-happened/ [ how using Domain Events or not using them can impact the Command Model and the projection of changes into the Query Model]

Application Services

• Application Services - 10 common doubts answered, Robert Pankowecki (23/12/2017). https://blog.arkency.com/application-service-ruby-rails-ddd/
• Services in Domain-Driven Design (DDD), Lev Gorodinski (14/04/2012) http://gorodinski.com/blog/2012/04/14/services-in-domain-driven-design-ddd/ [Shows full example with: application service PurchaseOrderService, aggregate root PurchaseOrder, value object Invoice, etc.]

Domain Events

• A better domain events pattern, Jimmy Bogard (2014/05/13). https://lostechies.com/jimmybogard/2014/05/13/a-better-domain-events-pattern/
• Domain Events vs. Integration Events in Domain-Driven Design and microservices architectures, Cesar de la Torre (07/02/2017). https://blogs.msdn.microsoft.com/cesardelatorre/2017/02/07/domain-events-vs-integration-events-in-domain-driven-design-and-microservices-architectures/
• Domain events: design and implementation. https://docs.microsoft.com/en-us/dotnet/standard/microservices-architecture/microservice-ddd-cqrs-patterns/domain-events-design-implementation
• Domain events: simple and reliable solution, Vladimir Khorikov https://enterprisecraftsmanship.com/2017/10/03/domain-events-simple-and-reliable-solution/
• DDD – Aggregate Roots and Domain Events publication, Paulo Clavijo https://paucls.wordpress.com/2018/05/31/ddd-aggregate-roots-and-domain-events-publication/

Implemented using Spring

• Spring - Domain event publication from aggregate roots, Mark Paluch (30/01/2017). https://spring.io/blog/2017/01/30/what-s-new-in-spring-data-release-ingalls#domain-event-publication-from-aggregate-roots
• Spring events and transactions — be cautious!, Zbigniew Artemiuk (30/10/2018) https://blog.pragmatists.com/spring-events-and-transactions-be-cautious-bdb64cb49a95
• Transaction Synchronization and Spring Application Events: Understanding @TransactionalEventListener, Bartłomiej Słota (04/08/2017) https://dzone.com/articles/transaction-synchronization-and-spring-application

Event Sourcing

• Scalable Microservices with Event Sourcing and Redis, Tom Mooney (13/12/2017) https://medium.com/lcom-techblog/scalable-microservices-with-event-sourcing-and-redis-6aa245574db0
• Don't Let the Internet Dupe You, Event Sourcing is Hard. Chris Kiehl. (02/03/2019) https://chriskiehl.com/article/event-sourcing-is-hard

Specification Pattern

• DDD and bulk operations, Vladimir Khorikov (28/10/2019) https://enterprisecraftsmanship.com/posts/ddd-bulk-operations/

Supporting Architectures

• DDD, Hexagonal, Onion, Clean, CQRS, … How I put it all together, Herberto Graça https://herbertograca.com/2017/11/16/explicit-architecture-01-ddd-hexagonal-onion-clean-cqrs-how-i-put-it-all-together/
• Hexagonal Architecture for Rails Developers, Victor Savkin (23/07/2016) https://medium.com/@vsavkin/hexagonal-architecture-for-rails-developers-8b1fee64a613
• Vertical Slice Architecture, Jimmy Bogard (19/04/2018) https://jimmybogard.com/vertical-slice-architecture/
• Is Layering Worth the Mapping?, Mark Seemann (9/1/2012) http://blog.ploeh.dk/2012/02/09/IsLayeringWorththeMapping
• How CQRS Works with Spring Tools, Jakub Pilimon (16/10/2018) https://thenewstack.io/how-cqrs-works-with-spring-tools/
• Real world implementation of the Clean Architecture, Jeroen De Dauw https://entropywins.wtf/slides/fun-architecture/index.html#/

Other

• Domain model purity vs. domain model completeness, Vladimir Khorikov (04/08/2020) https://enterprisecraftsmanship.com/posts/domain-model-purity-completeness
• Authentication and Authorization in DDD, José Luis Martínez (8/01/2016) https://medium.com/@martinezdelariva/authentication-and-authorization-in-ddd-671f7a5596ac
• Domain-Driven Design vs. Anemic model. How do they differ?, Kamil Berdychowski (03/01/2017) https://blog.pragmatists.com/domain-driven-design-vs-anemic-model-how-do-they-differ-ffdee9371a86 [Anemic model and bulky services vs Rich model and thin services]
• Refactoring from anemic model to DDD, Zbigniew Artemiuk (18/04/2017) https://blog.pragmatists.com/refactoring-from-anemic-model-to-ddd-880d3dd3d45f [refactoring repository to make it independent from implementation ...]

REST

• There is No U in CRUD, James Hood (25/07/2017) [resist the urge to follow the CRUD model for service APIs (use DDD to define your API in terms of domain objects and the business operations] http://jlhood.com/there-is-no-u-in-crud/

Q&A

Aggregates

• DDD - Fictitious Aggregate Root https://stackoverflow.com/a/46947901
• Consistency across Aggregate Root https://groups.google.com/forum/#!topic/dddcqrs/qf0EzujnDWA
• Aggregate roots coordinating their entities in an event sourcing system [Should an AR wrap the behavior of its entities?] https://groups.google.com/forum/#!topic/dddcqrs/T9bWd48e40I

Entities

• DDD Injecting Services on Entity Methods Calls [Is it within best practices of DDD and OOP to inject services on entity method calls?] https://softwareengineering.stackexchange.com/questions/357969/ddd-injecting-services-on-entity-methods-calls
• DDD - Persistence Model and Domain Model https://stackoverflow.com/questions/14024912/ddd-persistence-model-and-domain-model
• Spring Boot: How to keep DDD entities clean from JPA/Hibernate Annotations? https://stackoverflow.com/questions/58018542/spring-boot-how-to-keep-ddd-entities-clean-from-jpa-hibernate-annotations
• DDD - the rule that Entities can't access Repositories directly https://stackoverflow.com/questions/5694241/ddd-the-rule-that-entities-cant-access-repositories-directly

Talks

• Domain Driven Design: The Good Parts. Jimmy Bogard. (08/2016) https://youtu.be/U6CeaA-Phqo
• A Decade of DDD, CQRS, Event Sourcing. Greg Young. DDD Europe. (29/01/2016) https://youtu.be/LDW0QWie21s
• Eric Evans: What I've learned about DDD since the book. (2009) https://youtu.be/lE6Hxz4yomA
• Evil by Design, Jef Claes. (01/2016) [Visualization of events on a ES system] https://youtu.be/EmMvnB2v1GQ
• DDD Strategic Design With Spring Boot, Michael Plod. (2017) [Introduction to Bounded Context and Context Maps] https://youtu.be/DXbmfcgOvUI https://speakerdeck.com/mploed/ddd-strategic-design-with-spring-boot-examples
• Case Study: Practical tools and strategies for tackling legacy practices and legacy systems in a fast-growing startup, Alejandro Scandroli https://www.slideshare.net/ascandroli/case-study-practical-tools-and-strategies-for-tackling-legacy-practices-and-legacy-systems-in-a-fastgrowing-startup
• Case Study: tools and strategies for tackling legacy practices, Alejandro Scandroli. (2018) https://youtu.be/i8GzkkMWGYE [DDD strategic design, Wardley Maps, ...]
• Domain Language throughout Tests, combining DDD and BDD. Kenny Baas https://youtu.be/xSZnKnZ8EAo [event storming, feature mapping, example mapping, ...]
• From Legacy Chaos to the Promised Land of DDD, Anita Kvamme and Ellen Lippe, 2018 https://youtu.be/bnaYU4fjGe4 [...changing software architecture and code isn't really about changing software architecture and code, it's about the people, it's about each individual and the interaction between them, it's about helping team members changing habits, to mentor and teach new skills, most of all to work all align together as a team]
• DDD Lessons, Barry O'Sullivan (2018) [Domains and SubDomains are composable. Bounded Contexts are independent (not composable).] https://youtu.be/PMWl5X1sK70
• Language in Context, Eric Evans (2019) https://youtu.be/xyuKx5HsGK8

Presentations

• Adopting Domain Driven Design in your organization, Aleix Morgadas. (03/11/2018) https://docs.google.com/presentation/d/1Yiw6_u0rcJVHNBjnis56HdBiVg0-aGEMQPG06XG37zA
• DDD Modeling Workshop, Dennis Traub (22/10/2012) https://www.slideshare.net/Dennis_Traub/ddd-modeling-workshop
• Brownfield Domain Driven Design, Nicolò Pignatelli https://www.slideshare.net/NicolPignatelli/brownfield-domain-driven-design-48240538

Domain Events

• Domain Event - The Hidden Gem of DDD, Henrik Møller Rasmussen https://www.slideshare.net/heinodk/domain-event-the-hidden-gem-of-ddd

Functional DDD

• Functional architecture - The pits of success, Mark Seemann. (07/2016) https://youtu.be/US8QG9I1XW0

Supporting Architectures

• Evolutionary Software Architectures, Neal Ford [Technical Architecture vs Domain Architecture] https://youtu.be/CglSFhwbI3s
• The Actor Model, Hewitt, Meijer and Szyperski https://channel9.msdn.com/Shows/Going+Deep/Hewitt-Meijer-and-Szyperski-The-Actor-Model-everything-you-wanted-to-know-but-were-afraid-to-ask

Other Resources

• DDD Heuristics (Heuristics to share and use for designing software) https://www.dddheuristics.com/
• Domain-Driven Design Starter Modelling Process https://github.com/ddd-crew/ddd-starter-modelling-process

Sample projects

• DDD Sample Core https://github.com/citerus/dddsample-core
• IDDD https://github.com/VaughnVernon/IDDD_Samples
• BookARoom is a simple project to explain CQRS, Thomas Pierrain https://github.com/tpierrain/CQRS/blob/master/README.md
• Domain Driven Design Example C#, Zan Kavtaskin https://github.com/zkavtaskin/Domain-Driven-Design-Example
• All Things CQRS, A bunch of ways of doing CQRS with various Spring tools, Jakub Pilimon https://github.com/ddd-by-examples/all-things-cqrs
• Acerola: Hexagonal Architecture https://github.com/ivanpaulovich/hexagonal-architecture-acerola
• Project Spring DDD Bank, Christoph Knabe https://github.com/ChristophKnabe/spring-ddd-bank
• A comprehensive Domain-Driven Design example with problem space strategic analysis and various tactical patterns. https://github.com/ddd-by-examples/library

Katas / Exercises

• Transport Tycoon Exercises for DDD https://github.com/Softwarepark/exercises/blob/master/transport-tycoon.md