What do you do when requirements keep evolving, the timeline is tight, and your design’s application is growing ever more ambitious? Welcome to the world of special projects. This talk explores techniques for designing sensor systems that remain reliable when all else changes, with stories from real‑world design projects including a retrofit rangefinder receiver for an already‑fielded laser designator and a photochemistry instrument that brings scientific rigour to photocatalysed drug production, and shares practical insights for creating technology that meets the brief when the brief doesn’t (fully) exist.