CodEagle

In my previous blog post I made a proposal in the footnotes to rename the architecture that often comes along with the pattern CQRS. I thought of a “Circular Architecture” to clearly contrast it with a “Layered Architecture”. After a brief discussion with Greg Young and Alistair Cockburn about this I decided to take this idea under the microscope. They both claimed that the “Hexagonal Architecture” describes this architecture sufficiently. That got me thinking, since I respect both their opinions very much. First some definitions.

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Validation and business rules within a CQRS architecture [1][2] continue to raise issues for those who first hear of it. Three specific questions are often asked: how does the validation of commands work, how can one enforce business rules on large collections (state) and how does the enforcement of business rules on multiple aggregates work? Hopefully I can help some readers with my three replies. First the questions. read more…

During the evening of March the 17th, Sogyo will organize another technical seminar. In this one, Sogyo employees Rick van der Arend (that’s me!) and André Boonzaaijer will explain how we can handle the wishes of many of our customers to get an agile software project, in a domain driven way, but with a planned and fixed budget.

Experiences they have had in several recent projects will play a central role. Workshop techniques and several other activities you should undertake during the domain exploration phase will be presented. Next to that, Rick and André will answer the question: how do you fill and estimate the SCRUM product backlog up front? In short, this will be an interesting evening.

The seminar starts at 18:00 with a bite to eat and at about 19:00, Rick and André will start their intro. The program will last until about 22:00. Sogyo employees can subcribe to the seminar by sending an e-mail to marketing@sogyo.nl. If you are not a Sogyo employee, but you are interested in this seminar, please e-mail Anneke van Beek at avbeek@sogyo.nl

The last few week have been quite exhilirating! Two weeks of really exploring a domain, getting to know a new client’s business and language. I have always liked going through such a phase and one does not always get the chance to do something like that for two whole weeks at the client’s site. read more…