Why Rapido Uses a Static PIN (Rapid OTP Trade-offs)

If you use Rapido, you may have noticed the same four-digit Rapid PIN on ride after ride. Uber and Ola often lean on fresh SMS codes; Rapido leans on a stable number. The first engineering reflex is security discomfort: a static OTP sounds like a bug. In product terms it is usually a deliberate trade: availability and speed over per-ride cryptographic freshness, with a threat model built around physical pickup, not remote account takeover. This post breaks down why that design can make sense: fr