Brendan Gregg, Lead Performance Engineer at Joyent, analyzes performance and scalability throughout the software stack. As Performance Lead and Kernel Engineer at Sun Microsystems (and later Oracle), his work included developing the ZFS L2ARC, a pioneering file system technology for improving performance using flash memory. He has invented and developed many performance tools, including some that ship with Mac OS X and Oracle® Solaris™ 11. His recent work has included performance visualizations for Linux and illumos kernel analysis. He is coauthor of DTrace (Prentice Hall, 2011) and Solaris™ Performance and Tools (Prentice Hall, 2007).