In our earlier research work, we developed a conceptual framework that identifies the different types of roles that can exist in contemporary software development projects (including both agile and traditional software development approaches). The purpose of the framework is to assist software project managers when tuning software development project roles to the demands of individual projects, with our previous research indicating that there is a need to tailor software development roles to individual projects. In this work, we extend the earlier research through the use of a series of semi-structured interviews within seven Turkish software companies. The results, which are consistent with previous findings, offer further evidence of the usefulness of the framework, while also identifying possible areas for future work in this space.