The presence and importance of D-finite functions in combinatorics is on the rise. By definition, D-finite functions satisfy linear differential equations with polynomial coefficients, and they correspond to holonomic D-modules; indeed, they are often called holonomic functions. In this talk we will explore the D-module side of the story, and consider how we can, in certain cases, describe an algorithm to compute the scalar product of symmetric functions, and the consequences of this computation in enumerative, and algebraic combinatorics. We will also consider applications of the D-module point of view to efficiency improvements in recurrence manipulation, and in other coefficient extraction scenarios.