Recent Posts

The Ugly of Event Sourcing - Projection Schema Changes

7 minute read

Event Sourcing is a beautiful solution for high-performance or complex business systems, but you need to be aware that this also introduces challenges most people don't tell you about. Last year, I already blogged about the things I would do differently next time. But after attending another intr...

June 27, 2017

The Bad of Event Sourcing - The Pains of Wrongly Designed Aggregates

9 minute read

Event Sourcing is a brilliant solution for high-performance or complex business systems, but you need to be aware that this also introduces challenges most people don't tell you about. In June, I already blogged about the things I would do differently next time. But after attending another introd...

March 23, 2017

The Good of Event Sourcing - Conflict Handling, Replication and Domain Evolution

6 minute read

Event Sourcing is a brilliant solution for high-performance or complex business systems, but you need to be aware that this also introduces challenges most people don't tell you about. In @June, I already blogged about the things I would do differently next time. But after attending another intro...

February 19, 2017

The Good of Event Sourcing - Projections

5 minute read

It was in 2009 in Utrecht, The Netherlands, when I first learned about Event Sourcing and the Command Query Responsibility Segregation (CQRS) patterns at a training Greg Young gave there. I remembered to be awed by the scalability and architectural simplicity those styles provided. However, I als...

February 11, 2017

The three mental modes of working with unit tests

4 minute read

The other day, while pairing up on some unit test, I started to realize that I generally have three modes of looking at my unit tests. The Writing Mode While writing, I mostly focus on the mechanics of getting the test to pass. By then, I usually have a mental model and a particular scenario in ...

November 6, 2016