Brendan Gregg
Brendan Gregg is a computer programmer, system administrator, and author. Widely regarded as an expert on computer performance, he regularly speaks at conferences and is the author three books on the subject. Gregg is the creator of many open source performance analysis tools based on DTrace, Ftrace, and bcc/eBPF. He also invented a visualization technique called Flame Graphs which is used to spot performance bottlenecks in complex software programs.