• In complex systems the synchronization and coordination of many individual parts plays a crucial role. Examples range from multi-core computer architectures, power grid networks, coupled laser arrays, and wireless communication all the way to large groups of interacting cells during embryogenesis or in the brain. Information transmission necessary for the coordination of such large groups of interacting parts is often not instantaneous. This can introduce communication delays within the system which cannot be neglected. In associated mathematical models such delays in the interaction terms lead to qualitatively new behavior. Phenomena like coexisting stable solutions and dynamic behavior that depends nonlinearly on different system parameters can be observed.Detailed analysis of such systems is required to built efficiently designed industrial parts such as power saving micro-electronics or precisely synchronized clocks, as well as to understand the evolution and function of biological systems. Interdisciplinary teamwork, enthusiasm and strong communication skills to bridge different approaches and fields are important to successfully tackle these complex problems.