Mutation testing

Automated (unit) tests are a great way to continuously ensure that specific expectations about the software that you’re building are still being met. But did you know that your automated tests can deceive you? Do you know what the quality of your automated tests really is? Or, as the Roman Poet Juvenal put it much more eloquently:

Who will guard the guards themselves?

One of the techniques that can help you, your team and organization to get more insight into the quality of your automated tests is mutation testing.

Workshop contents

This workshop covers, among other things:

  • Ways in which your test automation can deceive you
  • Why coverage alone is not a good indicator of the quality of your tests
  • What mutation testing is and how it works
  • An overview of mutation testing tools
  • How to perform mutation testing using PITest (Java) or Stryker.NET (C#)
  • What mutation testing results can tell you
  • How to improve your application and test code based on mutation testing results

There’s no better way to learn than by doing, so you’ll be presented with a variety of hands-on (programming) exercises throughout this course.

Intended audience and prerequisite knowledge

This workshop is aimed at software development and testing practitioners that want to learn more about mutation testing and how to perform it using PITest or Stryker.NET. Some previous exposure to object-oriented software development and test automation will make it easier for you to follow along.

Delivery and group size

This workshop is a great fit both for an on site or an online in house training session, as well as a half or full day conference tutorial. I recommend a maximum group size of around 15-20 people.


This workshop typically takes 3-4 hours, but can be extended to a full-day tutorial.


If you would like to book me to teach this workshop in your organization or at your conference, or if you have any additional questions, please send an email to or use the contact form on this page.

For an overview of all training courses and workshops I have on offer, please visit the main training page.