Different Java implementations exist. Your code lives multiple lifes inside them and JIT compilers provide performance behind the scenes. Some JVMs have ahead-of-time (AOT) compilation that shortens the path. Statement of the problem is different, as well as solutions. Let's see why do we need pre-compiled code, how it can already be produced and used with Hotspot. How Project Graal lets Java to compile Java to native code and how new Java-Level JVM Compiler Interface incorporates Java to compilation work of JVM.