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 (R) Solaris (TM) 11. His recent work has included performance visualizations for Linux and illumos kernel analysis. For contributions to system administration, and his work on performance analysis methodologies, he is the recipient of the USENIX 2013 LISA Award for Outstanding Achievement in System Administration. He is also a coauthor of Dtrace: Dynamic Tracing in Oracle Solaris, Mac OS X and FreeBSD (Prentice Hall, 2011), and Solaris (TM) Performance and Tools: DTrace and MDB Techniques for Solaris 10 and OpenSolaris, (Prentice Hall, 2007).