Complex macromolecules in terms of structure and interactions play an important role in the properties of materials. An overview of the study of such systems discussing the main results and the key methods will be presented. As a first example, the case of bottle-brush with one and two types of side chains and the case of multi-block copolymers will be discussed as well as a comparison with theoretical predictions. To study the self-assembly of complex macromolecules one usually resorts to an effective potential, which enables the sinulation of largr systems. Then, assembly of these macromolecules based on this effective potential of a coarse-grained model. Relevant experiments and various aspects of modern computational methods will also be discussed