An important thrust in modern macromolecular chemistry is to construct complex architectures either directly from monomer units, or to design macromolecules capable of forming a desired superstructure by self-organization. Chain-rigidity is an example of a structural principle leading to self organization depending on the aspect ratio of the molecular objects and their mutual interactions. These molecularly defined objects serve as the building blocks of systems for which ultrathin layers composed of hairy rod macromolecules (HRM) are an example. Depending on architectural details layered architectures of HRM are models for molecular nanocomposites, exhibit interesting optical, electrochemical, dielectric or barrier properties. They are also designed to be used in devices the performance of which depends on molecular interactions. Thus, the design of novel macromolecules comprises the design of supramolecular architectures and functions based on architectural principles from the very beginning. A systems approach is emphasized as part of the synthetic strategy.