DDD Basics session with the Domain-Driven Design Belgium community. We only covered Strategic DDD, and split up the work amongst the five founders of the group: @yreynhout (Defining Domain-Driven Design) @JefClaes (Ubiquitous Language) @ONE75 (Context Mapping) @ToJans (Selling Domain-Driven Design to the business) @mathiasverraes (Bounded Contexts and Modelling). More at http://verraes.net/ or http://twitter.com/mathiasverraes

1. DDD Basics
February 11, 2014 - Olen, Belgium
wifi: ITR-Events / domaindriven

2. Kindly hosted by

3. Community Talks
Call for Proposals
domaindriven.be/cfp

4. Defining DDD (Yves)
Ubiquitous Language (Jef)
Bounded Contexts (Mathias)
Context Mapping (Stijn)
Modelling (Mathias)
Starting/Selling DDD (Tom)
Q&A / Lean Coffee

5. Bounded Contexts

6. Large complex systems:
increased cognitive load

7. Large complex systems:
divergence in
mental model

8. Large complex systems:
subtle nuances
in meaning

9. Avoid a
big
unified
centralised
model.

10. Split into
Bounded Contexts

11. Benefits:
clarity
model integrity
freedom to
evolve separately

12. Inspired by
departments
teams
life cycles
business processes
…

13. Make Bounded Context
explicit
pure
independent
consistent within its
boundary

14. Modelling

15. Structural modelling
Ontological

16. Structural modelling
inspired by
persistence concerns

17. Relational
Normalised
CRUD
Anaemic

18. Ask your Domain Expert
about
State Changes!

19. Why does it change?
When does it change?
How often?
Who causes it?
By which rules?
What consequences?

20. !
!
The moving parts are
more interesting than the
stable parts

21. !
!
A Domain Model
is about:

22. state + structure
behaviour + change
temporal
roles + actors
business rules + invariants
causality + correlation
interaction
processes
workflows + transitions
intention + consequence
failure …

23. Modelling:
Make the implicit explicit

24. example
!
Intentions:
Command Objects
Consequences:
Domain Events

25. @mathiasverraes
http://verraes.net