Building on the problem framing and viability assessments from the previous semesters, this course transitions students from ideation to execution. Students move beyond evaluating solutions and begin developing functional prototypes that address their identified grand challenges. The course introduces structured methodologies for iterative design, rapid prototyping, and user testing, equipping students with the tools to translate concepts into tangible, testable artefacts. Students engage closely with end users and communities to gather feedback and refine their prototypes through multiple cycles of iteration. Emphasis is placed on technical rigour, interdisciplinary collaboration, and the ability to communicate design decisions to both technical and non-technical audiences. The semester culminates in a prototype demonstration where teams present their solution, the design journey, and key learnings from user feedback.