Abstract: The classical Stepanov theorem strengthens the Rademacher theorem by establishing almost-everywhere differentiability for pointwise Lipschitz functions into Euclidean spaces. In this seminar, I will discuss my recent extension of the Stepanov theorem to a broader setting: pointwise Lipschitz functions between general metric spaces with a generalized notion of differentiability that unifies traditional differentiability in Euclidean spaces with Almgren's framework for multiple valued functions.