Before joining KAIST in December 2009, she worked as a Member of Technical Staﬀ in Sun Microsystems Laboratories, where she worked on formally designing and developing the Fortress programming language. Before that, she was a Research Associate in Computer Science at Harvard, where she worked on the Debugging Everywhere project. She received her Ph.D. (2001), M.S. (1996), and B.S. (1995), in Computer Science from KAIST. Her most recent research focuses on developing language features that are both useful in practice and proven to be sound. She led the effort to construct the core calculi of the Fortress language, to improve the Fortress prose speciﬁcation, and to build a full-ﬂedged parser for Fortress that runs entirely on the JVM.