Mack is the founder of Mack Real Estate Group and serves as its CEO. He is a co-founder of Mack Real Estate Credit Strategies and also serves as the CEO of Claros Fund Management, LLC. In addition, Mack is a consultant of Ares Management LLC and has been senior advisor of Ares Real Estate Group since 2013. He serves as a partner of the Apollo Real Estate Investment Funds and is responsible for new investments and investment management, and was North America CEO and managing partner of AREA Property Partners. Previously, Mack was a member of the real estate investment banking department at Shearson Lehman Hutton. He serves as a director of ARCap REIT Inc., Capital Apartment Properties II, Inc., and the Portico Group. He holds a J.D. from the Columbia University School of Law and graduated from the University of Pennsylvania's Wharton School of Business with a B.S. in economics..