She formerly served as an assistant teaching professor at Drexel University. She earned a juris doctor from St. John's University School of Law and a bachelor of science from Rutgers University. Professor Hallenborg has practiced real estate and construction law in New Jersey and New York for over 20 years, representing real estate developers, landlords, and public contractors before a variety of tribunals. She also is an experienced civil litigation mediator. She has published books, authored chapters, and written numerous articles on real estate topics, and has served as a source on real estate issues for The New York Times, the New York Daily News, and other media outlets. She currently serves on the board of the American Creativity Association.