Probably everyone has already become familiar with the mechanism of sealed classes introduced in Java 17. However, in addition to strict control of the class hierarchy, it also allows for the creation of non-obvious (yet facilitating) mechanisms. One of them will be enums on steroids - and that's what I want to talk about. But we won't just stop there - we'll follow the trail of everything that happened up to Java 21. It will definitely be an interesting journey - feel free to join !

The presentation allows to show in an accessible way, using the example of a loan engine (https://github.com/chrosciu/loan-engine), what has been recently changed in Java - up to version 21. Through its delivery, I have been awarded as the best speaker on Java track at 4Developers conference in Poznań. Additionally it would be delivered during Devoxx UK: https://www.devoxx.co.uk/talk/?id=12077. Recording from Geecon 2023 is available here: https://youtu.be/7DjyD_jv5Mc