Category Archives: DDD

Why use the command processor pattern in the service layer

Using a Command Processor When we think about a layered or hexagonal architecture it is common to identify the need for a service layer. The service layer both provides a facade over our domain layer to applications – acting as … Continue reading 


Why Repository SaveUpdate is a smell

One of the idioms I see a fair amount of is the SaveUpdate method on a Repository. The intent is usually to persist an item to storage, using a SaveUpdate method to lazily avoid the question of whether it is … Continue reading 


DDD/CQRS/Event Sourcing List

I know there is a large subset that reads this blog and/or follows me on twitter and/or is on the ddd list but for those who are not in those sets. In hope of bringing the DDD list back to … Continue reading 

Also posted in CQRS, Event Sourcing | 9 Comments

A Different Frame of Reference

Writing this in the Web UI which kind of sucks because I have not found a good blogging utility in unix yet. I kinda miss livewriter.   One of the biggest advantages of using Event Sourcing with CQRS is that … Continue reading 

Also posted in Event Sourcing, Testing | 14 Comments

It’s turtles all the way down

Normal 0 false false false EN-GB X-NONE X-NONE MicrosoftInternetExplorer4   Classically an ORM persists an object model to a relational model. Typically just use it to retrieve or persist the state of the objects in our model, not provide integration … Continue reading 

Also posted in Uncategorized | 5 Comments

Ubiquitous Language in Product Development

Hi there. I got this question from a fellow named Martin today: Real simple … most of the discussion on DDD surrounds the design in terms of the ubiquitous language. What if you are developing a product that is designed … Continue reading 

Also posted in contracts, dbc, spec# | 6 Comments

Introduction to NHibernate, pt. 7

In earlier parts of this series we looked at mapping via XML mapping files. I wanted to look at some alternatives to the angle bracket tax. First up is the Castle project’s Active Record. Next time we will look at … Continue reading 

Also posted in Uncategorized | 14 Comments

MSDN Mag 6/2009 Editor’s Note Sneak Peek – On Aggregates

One new thing I want to start doing on this blog is releasing early drafts of my editor’s notes.  There are a couple reasons for this. I want my ednotes to start being more technical anyway, and you good folks … Continue reading 

Also posted in Agile, Opinions | 9 Comments

My Horrible Lie

I have to admit that when I first started writing about DDDD I felt the need to separate its concepts from DDD. The reason for this is that the concepts being discussed were not in the mainstream of DDD. It … Continue reading 

Also posted in DDDD | 9 Comments


I will be doing a talk today for Alt.Net Europe’s VAN program  You can find out more information on the talk including the livemeeting address here   I will be talking about command query separation  in DDD based systems. … Continue reading 

Also posted in DDDD | 8 Comments