Abstract—The development of complex software sys-tems requires a mixture of various technical and non-technical competencies. While some guidelines exist which technical knowledge is required to make a good software engineer, there is a lack of insight as to which non-technical or soft skills are necessary to master complex software projects. This paper proposes a body of skills (SWEBOS) for software engineering. The collection of necessary skills is developed on the basis of a clear, data-driven research design. The resulting required soft skills for software engi-neering are described precisely and semantically rich in a three-level structure. This approach guarantees that skills are not just characterized in a broad and general manner, but rather they are specifically adapted to the domain of software engineering.