From 1971 he is affiliated with the Systems Research Institute of the Polish Academy of Sciences, from which he received his scientific degrees.
He is also Professor in Graduate School for Applied Informatics and Management in Warsaw.

The scientific interests of Professor Kaliszewski are in optimization, multiple criteria decision making, computer-aided decision making, and also in identification, quantification, and management of risk in business organizations.

He confronts his scientific interests and achievements in realm of business.

• In 1994 - 1995 he worked as an analyst in Polish Development Bank.
• In years 1995 - 1996 he worked on establishing Warsaw Board of Trade, and in years 1997 - 2003 in National Depository for Securities (a depository and a clearing house) on a clearing system for derivative trading on Warsaw Stock Exchange and Electricity Exchange.
• In 2004 - 2005 he was the advisor to CEO and the leader of a team implementing New Basel Accord in BISE bank.
• In 2007 - 2008 he held position of Scientific Secretary in Instute of Mathematical Machines.
• In 2008 - 2009 he was proxy to CEO, and in 2009 - 2010 he acted as director of Scientific Office in Telecommunication Institute (Przemysłowy Instytut Telekomunikacji S.A.)

Professor Kaliszewski published over 100 scientific research papers, three research monographs:

(Quantitative Pareto Analysis by Cone Separation Technique, Kluwer, 1994,

Soft Computing for Complex Multiple Criteria Decision Making, Springer, 2006,

Multiple Criteria Decision Making by Multiobjective Optimization – A Toolbox, Springer, 2012, co-authors - J. Miroforidis and D. Podkopaev,

and over 30 popular papers on risk management in finance and electrical energy trading.

He is a founding member and currently the Vice Chairperson of the Poland Chapter of The Institute for Operations Research and the Management Sciences (INFORMS), a member of the Polish Mathematical Society, and the Polish Society for Operational and Systems Research.

His favorite avocations include horse riding, downhill skiing, sailing and scuba diving.