Are your tests good enough?

In November 2025 the very fist edition of Voxxed Days Crete took place with an amazing line-up of speakers and topics. With more than 30 speakers and 300 attendees, the event was a great success and a great opportunity to meet and share knowledge with many people from the software development community.

During this event I had the pleasure to be one of the speakers and present my talk “Are your tests good enough?” in front of a great audience. The abstract of the presentations was the following:

If we use tests to test code, how can we test our own tests? We write tests in order to assure the quality of the software we are writing. Software developers are usually trying to reach a certain level of code coverage through their tests. However, the quality of the tests is not usually measured or examined through this process. It is possible that someone can even achieve a high code coverage even without any assertion at all! This makes our test suite not to fail even after major code changes. In this session we will examine why and when a test can be considered as good or bad in terms of testability and also move on and examine how mutation tests can allow us to test our tests in terms of efficiency. We will investigate when we should run mutation tests, how to interpret the given results, and also how to generate appropriate variations.

You can access the video recording of the presentation here:

The slides of the presentation are available here in PDF format.

It was a great experience to be part of this event and share my knowledge with the community. I am looking forward to the next edition of Voxxed Days Crete and to meet again with all the amazing people I had the chance to meet during this event.