The heterogeneity characterizing the systems populating the Ubiquitous Computing environment prevents their seamless interoperability. Heterogeneous protocols may be willing to cooperate in order to reach some common goal even though they meet dynamically and do not have a priori knowledge of each other. Despite numerous efforts have been done in the literature, the automated and run-time interoperability is still an open challenge for such environment. We consider interoperability as the ability for two Networked Systems (NSs) to communicate and correctly coordinate to achieve their goal(s). In this paper, we report the main outcomes of our past and recent research on automatically achieving protocol interoperability via connector synthesis. We consider application-layer connectors by referring to two conceptually distinct notions of connector: {\em coordinator} and {\em mediator}. The former is used when the NSs to be connected are already able to communicate but they need to be specifically coordinated in order to reach their goal(s). The latter goes a step forward representing a solution for both achieving correct coordination and enabling communication between highly heterogeneous NSs. In the past, most of the works in the literature described efforts to the automatic synthesis of coordinators while, in recent years the focus moved also to the automatic synthesis of mediators. By considering our past experience on the automatic synthesis of coordinators and mediators as a baseline, we conclude by overviewing a formal method for the automated synthesis of mediators that allows to relax some assumptions state-of-the-art approaches rely on, and characterize the necessary and sufficient interoperability conditions that ensure the mediator existence and correctness.