Code profiling is notoriously difficult to do well in a server side application. You often can't
run traditional JVM-based profilers on a remote server, or leave them installed in
deployed applications.
Profiling was developed by Atlassian because we needed it
to profile our J2EE applications (like JIRA).
It helps us, we hope it helps you!
Like any other library that comes in a jar. Just make sure it's on your application's classpath.
Also see configuration for how to configure Atlassian Profiling, and
code profiling to learn how to profile your own code.