Professor Guarino's professional career has been in the financial services industry, with such corporations as TIAA-CREF, Met Life, and The Bank of New York Mellon. He was a full-time instructor at Stevens Institute of Technology in Hoboken, New Jersey, and currently, is at Rutgers University in Newark. His teaching background includes graduate and undergraduate courses in macroeconomics and microeconomics, as well as managerial accounting, financial management, corporate finance, portfolio theory, financial institutions and markets, and investment analysis.

Professor Guarino received a B.A. in Political Science, M.B.A. in Finance and a graduate certificate in International Business from Seton Hall University. He also has a Master's degree in International Relations from the Maxwell School at Syracuse University, and received his J.D. from Rutgers University School of Law in Newark.