 At age 37, having sold Yurie, he stayed on with Lucent, serving first as president of carrier networks (1998-1999), then as president of the optical networking group (2000-2001), where he orchestrated a multibillion-dollar business turnaround that propelled Lucent's worldwide market share position from #4 in the optical space to #1 in four fiscal quarters.In 1999, Kim co-founded Taconic Capital Advisors LLC, an event-driven and multi-strategy hedge fund firm, along with Kenneth Brody and Frank Brosens.Kim took a hiatus from Lucent in 2002 to join the University of Maryland faculty, with joint appointments in the Department of Electrical and Computer Engineering and the Department of Mechanical Engineering.