Engineering design is considered an effective means for developing engineering technical skills. Normally, engineering design is conducted in teams and is a collaborative open-ended approach under constraints. This nature of engineering design involves engagement of several interpersonal, cognitive, and management skills or competencies such as teamwork, communications, decision making, problem solving, etc. While modern engineers are supposed to be technically competent, they need to posses a wide set of interpersonal, cognitive, and management competencies to function effectively in the workplace. Increasingly there has been more deployment of engineering design competitions (EDCs) in engineering education to address some gaps in current curricula system. In this study, the impact of a complex engineering design competition on developing 21st century competencies of engineering and technology talent is investigated. A mix of quantitative and qualitative methods in the approach to self-reporting perceptions were utilized. Data was collected through interviews from students and faculty, and through surveys from students. Triangulating quantitative and qualitative data from students and faculty indicate that the investigated EDC have positive impact on a large set of 21st century engineering and technology competencies, this has been consistent across groups of students from the EU, Middle East, and Asia, as well as across genders. This is one of the few available investigations that sheds light in further depth on the impact of engineering design on non-technical skills.