Explore the performance enhancements and potential pitfalls of upgrading to Java 9 in this 54-minute Devoxx conference talk. Delve into the impressive 91 JEPs included in JDK 9, focusing on the quarter dedicated to performance improvements. Examine changes in the language, core libraries, and JVM itself. Learn about new features like Compact Strings, improved String operations, and enhanced Collections. Discover the benefits of the new default Garbage Collector and the Invoke Dynamic approach. Gain insights into possible performance regressions and considerations for upgrading. By the end of this talk, acquire the knowledge needed to evaluate whether the effort of upgrading to Java 9 is worthwhile for your projects.