For most workloads, Java 21 is the fastest Java version ever released. In this short talk, we will take a peak under the hood and explore some of the performance improvements that were made in recent Java versions and how old classes even from Java 1.0 (like RandomAccessFile) were made much faster with no change in user code calling the improved classes. We will also explore some future enhancement candidates and learn how performance is usually measured by committers to the Open JDK.

Buckle up for a quick ride!

Recorded at Devoxx Belgium 2023