Addressing the complexity of concurrency programming in the context of changing hardware remains an ongoing challenge. Overcoming limitations of conventional concurrency, I have investigated several ways of concurrency correctness verification in Scala. Initially, I investigated the transformation of software contracts into test-oracles to perform fully automated testing, a concept known from ongoing research in Eiffel. Therefore, I investigated several Design by Contracts tools and finally developed f-DBC, a novel tool based on a flexible component architecture for supporting functional Design by Contract in Scala. An performance analysis provides evidence that contracts written in f-DBC do not cause any measurable reduction in run-time performance compared to the