Many complex issues in engineering involve decision making by managers, technology users, or engineers under conditions of risk and uncertainty. In this challenge-based learning course, students work toward an acceptable technical solution to a problem relating to clients such as those encountered in previous courses in the sequence. Examples include safety and risks factors associated with battery recycling, hydrogen production and storage, the introduction of a plasma plaster, privacy preserving contact tracing, or key management. Using theoretical and technical knowledge from the specialized course, students assess possible technical solutions for acceptability and develop solutions that are acceptable to relevant stakeholders/ clients. They communicate the proposed solution(s) to a client in a presentation at the end of the course.