Heterogeneous non-functional requirements of Distributed Real-Time Embedded (DRE) system put a limit on middleware engineering: the middleware must reflect application requirements, with limited runtime impact. Thus, building an application-tailored middleware is both a requirement and a challenge. In this paper, we provide an overview of our work on the construction of middleware. We focus on two complementary projects: the definition of middleware that provides strong support for both tailorability and verification of its internals; the definition of a methodology that enables the automatizing of key steps of middleware construction. We illustrate how our current work on PolyORB, Ocarina and the use of Petri Nets allows designer to build the middleware that precisely matches its application requirements and comes with precise proof of its properties.