· Professor, Northwestern University2024–
· Director, Northwestern University Argonne Laboratory Institute For Science And Engineering, Argonne National Laboratory2014–2024
· Director, Exascale Technology And Computing Institute, Argonne National Laboratory2010–2014
· Director, Argonne Leadership Computing Facility, Argonne National Laboratory2008–2010
· Computer Scientist, Chief Architect Leadership Computing Facility, Argonne National Laboratory2004–2008
· Director Of Engineering, TeraGrid, Argonne National Laboratory2002–2004
· Vice President Of Engineering, TurboLinux2000–2002
· Scientist, Los Alamos National Laboratory1996–2000
· Postdoc Researcher, Indiana University1992–1996
· Ph.D., Computer Science, Indiana University Bloomington1985–1993