DECOS is a meeting point for scientists, educators, students and experts interested in various aspects of complexity. The main purpose of the conference has remained the same throughout the period of the last ten years – since it started as a workshop CSNSS, the Complex Systems in Natural and Social Sciences - to facilitate the exchange of ideas and to present the state-of-the-art of the complex systems research and education. This year’s meeting will cover a host of interdisciplinary topics ranging from numerical simulations in natural and technical sciences, modelling of social and mental phenomena, to meta-theories and philosophical investigations of complexity.