“Design Week” is an assessed group-based project in the Department of Mechanical Engineering at Imperial College London. It is designed to enable second year students to experience the entire design process in one week, and apply fundamental knowledge gained from the first year and a half of their undergraduate (UG) studies. This includes coping with uncertainty created by a more authentic and deliberately, less defined brief. This paper explores the design and delivery iterations of Design Week, and the motivations and educational rationale behind this format, including critical consideration of how to take into account the different student emotions that experiential learning can provoke. During Design Week, all other educational activities (lectures, tutorials and labs) are suspended to allow students to work in groups of four to develop a concept (proposed by a fictional client) in an immersive 'full-time' mode. A member of academic staff is assigned to each group as a facilitator to guide the students in their decision-making, but not give direct advice. Assessment of students' learning over Design Week comprises four elements: daily submissions which are compiled into an oral presentation at the end of the week (30 %), individual engineering logbooks (30 %), a group poster presentation (10 %), and an individual conduct of task mark (30 %). A peer-feedback system is implemented to aid accountability between students. Our experience gained from iterations of this module and student data offer insight into the ways in which students navigate this challenging process, building self-efficacy as they do so. This more authentic approach replaces a typical assessment (e.g. coursework or summative exam) and instead provides an insight into what a real-life design project might look and feel like. It is a successful, alternative means of assessing which is received favourably by students and staff.