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.

RydeNow is a ride-hailing app for Android. While your driver is on the way, it posts a persistent foreground notification with quick action buttons like "Share trip" and "Cancel ride" so riders can act without opening the app. The notification actions are wired up using PendingIntents that other system components fire on the app's behalf. Review the notification layer and decide whether those action buttons are safe to ship.

GateRush is a Java Spring Boot ticketing platform used for stadium check-in, ticket transfers, and guest lookup during live events. The `attendeeSearch(pattern:)` GraphQL field helps staff find names quickly from large event rosters. Review how the search pattern is handled before it is run over thousands of attendee records.

TollGate is a payments backend that fulfills digital orders for an online game store. When a customer pays, the payment provider (PayRail) sends a signed webhook to TollGate, which verifies the HMAC signature before flipping the order to PAID and releasing the game keys. The signing secret never leaves the server, yet finance keeps reporting orders marked paid that PayRail has no record of. Review how the incoming webhook is authenticated.

LedgerLink is a B2B invoicing SaaS where suppliers upload invoices in the standard UBL XML e-invoice format. The platform parses each upload to extract line items and totals, then renders them back in the supplier dashboard. The accounting team recently noticed odd values appearing in invoice fields. Review the XML ingestion pipeline and find the flaw that lets a malicious supplier read server-side data.

ReceiptPad is a bookkeeping API for freelancers who need to generate shareable PDF receipt packets for clients. The export endpoint preallocates a response buffer to keep large receipt downloads fast. Review the PDF export flow, especially the interaction between requested page count, unsafe buffer preallocation, and the bytes returned in the HTTP response.

BackstagePass is a Spring Boot festival operations portal that emails encrypted, single-use invitations to artists and crew. The team recently introduced friendly error responses for damaged invitation links. Review how token decryption failures become HTTP responses at `GET /crew/accept`. A forged organizer invitation could let an attacker take over festival operations and replace ticket-sale payout details.