Steven has been working on the Linux kernel since 1998 (started while working on his masters). He has been working on the Linux kernel professionally since 2001. Steven is one of the original developers of the PREEMPT_RT patch which turns Linux into a true real-time operating system. Steven is also the original developer and current maintainer of Ftrace (the official tracer of the Linux kernel). Steven has also created an open source user space tool to interact with Ftrace called trace-cmd, and a GUI for that tool called KernelShark. Steven is now leading a development to rewrite KernelShark and extend it beyond just the Linux kernel. Steven has given talks all over the world on various aspects of Linux. He is part of the Linux Foundation Technical Advisory Board, and on the Linux Plumbers Program Committee. Currently Steven works for VMware as an Open Source Engineer, promoting Open Source both inside and outside the company.