In this Dagstuhl Seminar we aim at investigating the convergence of the theory, algorithms, and tools for contract reasoning at two complementary levels: system level and software level. The goal is to support the definition of a seamless, end-to-end integration of contract-based design from abstract system descriptions over verified software components down to the final deployment. We plan to bring together the two communities and to discuss the following themes: How can system and software contracts be harmonized, in order to ensure traceability? What is the required expressiveness to formalize quantitative properties? How can contract inference and abstraction be automated? How can contracts be validated?