DDD Europe 2023 - Program

Playing with domain models in code

Main Conference - Hands-on Lab


Nico Krijnen and Jettro Coenradie

Nico KrijnenJettro Coenradie
Thursday 8 from 11:00 until 13:00 in Room 2

(This is a hands-on lab with limited capacity)

Two brains, one domain, one laptop, and a guarantee for 2 hours of fun and learning. You’ll go back to basics. Talking about the domain, designing the model and explore coding the model in Java or Kotlin with close to no libraries.

This is a hands-on coding workshop where you will work in pairs together with other participants. Your base will be the output of an EventStorming session and some context about the domain that you'll be modeling. Together, you'll play around, modeling parts of the domain in code, using tests to guide your design.

A starter project will be provided to get you up and running quickly, you can choose between Java or Kotlin. All you have to bring is a laptop with a recent version of IntelliJ installed (only one laptop per pair is needed). Throughout the workshop, pairs will share their approach so we can all learn from each other.

What you will learn:

  • Why you need to start by understanding the problem before you start coding.
  • How to 'sketch' in code and tease out a model bit by bit.
  • Not to be afraid to throw away the model and sketch again.


Bring a laptop and make sure you install IntelliJ on it beforehand so you can have a running start. All preparation instructions will be in the following github repo: https://github.com/nkrijnen/workshop-ddd-europe-2023-06

About Nico Krijnen

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Nico Krijnen is a Cloud Solution Architect at Luminis. He helps organizations to translate available options into practical solutions for complex problems. For a big chunk of his career, he disrupted the DAM space by building an innovative visual file management solution called Elvis, which is being used by media organizations all over the world. Besides leading teams and giving direction, he likes to roll up his sleeves and experience first-hand how (and whether) the latest technologies work in the real world. He is never shy of making unconventional choices to achieve radical results.

Recordings: https://youtube.com/playlist?list=PLpsPwCgJlHhyONy7_4fb-AfYcmAS0oD7P Slides: https://speakerdeck.com/nicokrijnen

About Jettro Coenradie

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Jettro is a software architect, search relevance geek, and data enthusiast that loves to talk about his job, hobbies, and other things that inspire people. Jettro truly believes in the Luminis mantra that the only thing that grows by sharing is knowledge. After more than ten years of creating the best search engines for multiple customers, Jettro is drawn into Machine Learning and Natural Language Processing. Learning and talking about NLP is what drives him to keep improving the user experience of search engines.