Recorded at SpringOne2GX 2015. Speaker: Ashley Puls, NewRelic Core Spring Track Slides: http://www.slideshare.net/SpringCentral/what-it-means-to-be-just-in-time We write Java code on a daily basis which then gets compiled down to bytecode and run on the JVM. This talk explains what happens to bytecode inside the JVM. It begins with an overview of the Just In Time (JIT) compiler. This overview discusses JIT optimizations such as method inlining and loop unrolling. The talk then inspects JIT logs to explain the optimizations performed on a spring boot application. By the end of the talk, you should be able to examine the impact of the JIT compiler on your own code.