This paper discusses the use of the "Theory of Didactic Situations" (TDS) at university level, paying special attention to the constraints and specificities of its use at this level. We begin by presenting the origins and main tenets of this approach, and discuss how these tenets are used towards the design of "Didactical Engineering" (DE), particularly adapted at the tertiary level. We then illustrate the potency of the TDS-DE approach in three university level "Research Cases," two related to Calculus, and one related to proof. These studies deploy constructs such as "didactic contract," "milieu," "didactic variables," and "epistemological analyses," among others, to design "Situations" at university level. We conclude with a few thoughts on how the TDS-DE approach relates to other approaches, most notably the Anthropological Theory of the Didactic.