Upgrading the language version has never been such a heatedly debated topic in the entire Java history. One in three teams that I work with is ‘transitioning’ to a newer version, be it Java 11, 17, or even 21, while some projects even leap two LTS versions at once. That’s amazing! You can finally use all these new shiny features: immutable collections, records, sealed types, enhanced switch, text blocks, virtual threads ... but which of these can become game changers for your project? Which ones are worth the risk of refactoring your old code to use them? Don’t miss this critical review of the best practical use cases of the modern Java features.