Jurijs Čudnovskis from “Craftsmans Passion” will give a talk “Do we need DDD?“. While helping to build and scale multiple IT companies and during tons of interviews I’ve seen a lot of misunderstanding of Domain Driven Design. I would like to share with you my experience based point of view on why and how DDD can help you and your company to build better, more flexible and scalable software and solve real business needs. The talk will be not so much about technical aspect of DDD, but about core ideas behind with some real world examples. :) (Language – English) For more than 10 years Jurijs is helping multiple organizations to build their products and grow their companies. His passion is to find easiest solution for complex business problems and build excelent business oriented IT teams.

1. Do we need DDD?

5. Inheritance and Polymorphism

9. 1. Rework

10. 2. Lack of
purpose

11. 3. Boring
meetings

12. 4. Big ball of
mud

13. –Robert C. Martin (Uncle Bob)
http://blog.cleancoder.com/uncle-bob/2011/09/30/Screaming-Architecture.html
“Screaming architecture”

14. HELP ME!!!!

15. 5. Long disputes
about
frameworks and
technologies

16. 6. Naming
struggle

17. Symptoms
Rework
Lack of purpose
Boring meetings
Big ball of mud (Messy architecture)
Never-ending disputes about technologies
Naming struggle

18. Domain driven design

19. DDD in 60 seconds
Ubiquitous language
Domain model and subdomains
Bounded context
Domain logic

20. Example for PSP
Client
Account
Payment

21. Example for Client
Client n -> n Representative 1 -> n AuthenticationMethods
Client 1 -> 1 Private Person
Client 1 -> 1 Legal Person
Client 1 -> n Contact Information

22. private class InitiatePaymentAction {
private AccountRepository accounts;
private paymentRepository payments;
public AcceptedPayment execute(PendingPayment pendingPayment) {
var account = accounts.findRequired(pendingPayment.fromAccount)
account.checkEnoughBalanceFor(pendingPayment)
var payment = new Payment(pendingPayment);
payments.place(payment);
return payment;
}
}

23. private class InitiatePaymentAction {
private AccountRepository accounts;
private paymentRepository payments;
private ComplianceService compliance;
public AcceptedPayment execute(PendingPayment pendingPayment) {
var account = accounts.findRequired(pendingPayment.fromAccount);
account.checkEnoughBalanceFor(pendingPayment);
var payment = new Payment(pendingPayment);
// broadcasts PaymentUnderReviewEvent in case not possible to auto accept
compliance.review(payment);
payments.place(payment);
return payment;
}
}

24. private class InitiatePaymentAction {
private AccountRepository accounts;
private paymentRepository payments;
private ComplianceService compliance;
private PaymentRouter paymentRouter;
public AcceptedPayment execute(PendingPayment pendingPayment) {
var account = accounts.findRequired(pendingPayment.fromAccount);
account.checkEnoughBalanceFor(pendingPayment);
var payment = new Payment(pendingPayment);
// broadcasts PaymentUnderReviewEvent in case not possible to auto accept
compliance.review(payment);
paymentRouter.chooseRouteFor(payment);
payments.place(payment);
return payment;
}
}

25. KYB and KYC

26. Business
Offers
Customer
Needs
KYB and KYC
Constraints

27. –Too many authors :)
“Design is inevitable. The alternative to good design is bad design.
Not no design.”

28. Q & A

29. Thank you!