Brendan Gregg is the lead performance engineer at Joyent, where he analyzes performance and scalability at any level of the software stack. He is the author of the upcoming book "Systems Performance" (Prentice Hall, 2013), and co-author of "DTrace" (Prentice Hall, 2011) and "Solaris Performance and Tools" (Prentice Hall, 2006). He was previously a performance lead and kernel engineer at Sun Microsystems where he developed the ZFS L2ARC, and later Oracle. He has also invented and developed numerous performance analysis tools, including some that are shipped by default in Mac OS X and Oracle Solaris 11. His recent work has included performance visualizations for illumos and Linux kernel analysis.