Handback

A privacy-first way for neighbors to return misdelivered packages: a finder scans the label, and only the ID-verified recipient ever learns a match exists. As the sole engineer across iOS, Android, and the backend, I shipped it with about 1,100 tests, 38 gated releases, and a vision OCR pipeline that took real-label extraction from 0/18 to 5/5 while cutting image-token usage by 38%.