Designers often assume a scrapped project's impact disappears with it, but preliminary evidence exists if they defined and collected the right signals early. A signal is an observable user behavior change—visible in prototypes or usability tests, not requiring launch—that predicts whether a design achieved its intended effect. Unlike lagging metrics (revenue) or leading metrics (activation rates) that need a live product, signals can be captured before shipping, giving designers a lasting record of impact even when projects get cancelled.