Java Byte code is OS independent, which means that your application's startup takes more time than a native image. Using the Class Data Sharing functionality introduced in more recent versions of the JVM, you can prepare your application so that it will load very fast. In this presentation, I'll go into more detail what Class Data Sharing is and how you can use it on an OpenJDK versions. With some Jakarta EE demo applications, you will see gains that you can achieve and reduce memory footprint a lot in Docker containers by sharing memory.