Mathias Verraes

Summary Event Instead of emitting a stream of Domain Events, emit a single Summary.

Video for my DDD eXchange 2018 keynote in London Abstract Software design principles aspire to be universal.

Video of my DDD eXchange 2017 talk in London Video of my ExploreDDD 2017 talk in Denver Abstract Modelling is more than knowledge management.

Video of my keynote at Neos Conference 2017 in Hamburg

Video of my talk at Agile Testing & BDD eXchange 2016 in London Video of my talk at the DDD London meetup Slides: Abstract “Make the implicit explicit” must be one of the most valuable advices I ever got about software modelling and design.

Video & slides for my NCrafts talk on software metaphors.

I submitted proposals to conferences for almost two years before getting accepted.

Technical Debt is a great metaphor.

Video for my CukeUp 2016 lightning talk in London

Gated pre-merge code reviews are bad.

Below is an attempt at illustrating a design/redesign process I went through at a client, who’s started refactoring the core systems their business depends on.

The video & slides for my keynote at NCrafts 2015 in Paris.

I was at a client recently, a large insurance and banking company.

Visual storytelling through Event Storming Last week, my client’s Chief Product Owner announced to the team they would introduce a set of new requirements using Event Storming, “as Mathias has taught us”.

Many of the frameworks I’ve worked with, promise to separate responsibilities with MVC.

A message is a unit of communication between systems.

Joint post with Konstantin Kudryashov.

Figuring out how much unit tests you need to write, can be tricky, especially if you are new to Test-Driven Development.

“Programming Erlang: Software for a Concurrent World, 2nd ed” by Joe Armstrong, is not just a great introduction to the language, but also offers a glimpse into the “Let It Crash” philosophy that drives it.

Let’s have some fun with higher order programming in PHP.

The slides for my talk at Build Stuff in Vilnius.

Boundaries & Messages A system’s design is defined by it’s boundaries, and by the way it communicates with other systems.

Presentation delivered at DrupalCamp Ghent, November 2014 No slides?

“Software design is just theory.”

My blog post on Small Uncontrolled Experiments landed me an invitation to speak at Agile Cambridge.

A lot of so-called Object-Oriented Programming1 is in fact nothing more than procedural code wrapped in objects.

Video The talk that I mention is The Framework as an Implementation Detail by Marcello Duarte and Konstantin Kudryashov.

On Estimation The Cost of Estimation Sterile Estimation To reduce the risk of incidents, the FAA imposed the so-called “sterile cockpit” regulation.

Benjamin Eberlei did a really nice job of explaining refactoring the Feature Envy code smell on his blog.

Have a look at these two classes: <?

Inspired by Tim Schraepen’s experience report, I thought I’d list some recent experiences with facilitating Event Storming sessions.

Update 2021-05-23 I wrote about the “It's Just Like...”

Debt is good.

On Estimation The Cost of Estimation Sterile Estimation Ballpark Figures When somebody asks you to estimate how long a feature or a project will take, you will estimate the shortest possible time in which you can complete it.

Some of the reactions to my last blog post on Named Constructors in PHP, originate from the notion that static methods are inherently bad and should never be used.

PHP allows only a single constructor per class.

See the slides at Speakerdeck Abstract In the software industry, the life expectancy of ideas, methodologies, and technologies, is extremely short.

I’ve been dabbling with Functional Programming languages for a while now.

I make all my classes final by default.

Update 2021-01-25: I used to call this “small controlled experiments”.

Video Slides Abstract Traditionally, we create structural models for our applications, and store the state of these models in our databases.

Should you always speak and write perfect Oxford English?

Context is everywhere.

Yesterday, we did a DDD Basics session with the Domain-Driven Design Belgium community.

Context Mapping, first described by Eric Evans in Domain-Driven Design, is lightweight method of drawing out the relations between systems, and parts of systems.

We can’t avoid failure.

If I give you half a million euros, you will be quite happy.

If I had asked people what they wanted, they would have said faster horses.

I hadn’t done any presentations or blog posts about Command/Query Responsibility Segregation yet, even though I’ve been working with it for more than year (and have been wanting to use it for another year).

I got this mail from a listener of the podcast episode on Value Objects I recorded with Konstantin: I've been listening to your Elephant in the room podcast Episode #002, i was wondering if you have a coding example of where you use the Country as a value…