Niels Sørensen has been using Mathematica in his research since 1996 at various universities and in industry. While at Brown University (1995–1996), Sørensen used Mathematica for the study of the spectra of a series of differential operators originating from a two-dimensional fourth-order PDE. At Lund University (1996–2002), his research with Mathematica involved finding all complex solutions to a series of algebraic equations, and he used Mathematica as a testing and algebraic tool when developing non-linear finite element programs for the study of materials mechanics. At Lund he also used Mathematica for reference calculations when teaching tensor-analysis and continuum mechanics. Later he worked with the Danish Defense Intelligence Service (DDS) in the areas of discrete mathematics and high-performance computing and with life insurance mathematics software development at Forca A/S.

At Gmech, Sørensen, together with actuary Claus Poulsen, developed very general, fast actuarial risk tools used for N-state continuous stochastic processes with time-dependent parameters, parameter-estimation, cash-flow computations, and Solvency II calculations. Sørensen recommends Mathematica as an independent actuarial testing tool and for reference computations due to its state-of-the-art numerical capabilities.