PetPal Prints lets pet owners upload photos and captions for custom mugs. The team added rich captions so customers can link to rescue shelters, and flagged orders now appear in a staff moderation queue before printing. Review how saved captions move from the public order form into the moderation dashboard, especially where the Leaf template decides whether to escape or trust the caption.

ModelBazaar is a marketplace where data scientists upload trained models (.pt, .pkl, .joblib) for others to buy and download. To make listings attractive, the backend automatically runs a quick sample inference on every uploaded artifact so the product page can show a live demo. Review the upload and demo pipeline and find the critical flaw that lets a malicious uploader compromise the marketplace's servers.

PaceMate is an iOS running tracker that lets users sign in with their social account through a third-party OAuth provider. To receive the authorization response, the app registers a custom URL scheme (pacemate://oauth-callback) in Info.plist and completes login when iOS hands it the redirect. Review how the app starts the sign-in flow and consumes the returned authorization code.