Martijn Verburg is the co-founder & CEO of jClarity - a Java/JVM performance tools company. He is the co-leader for the LJC (aka London JUG), from which he runs the global Adopt OpenJDK and Adopt a JSR programmes, two open source projects (PCGen and Ikasan EIP), and is a bartender at the Javaranch. You can also find him answering thorny questions at the Programmers StackExchange.
He's a regular speaker at conferences (FOSDEM, JavaOne, OSCON, Devoxx etc) and is the co-author of "The Well-Grounded Java Developer" (Manning publications).
Martijn was recently selected a Java Champion in recognition for his contribution to the Java ecosystem There are rumors that he might be the infamous Diabolical Developer, but that's clearly just a lie.
The Diabolical Developer shows you the steps to take when you get a call at 3:00am saying that your Java / JVM application is too slow. He introduces the Performance Diagnostic Methodology (PDM) which focuses on how to quickly hone into the root cause of a bottleneck and what steps you can take to fix it. After this session you should only have to take hours, instead of days or weeks to pinpoint performance issues in your apps.