New Delhi, Aug. 26 -- For one French tourist, the ultimate Indian marvel isn't some historical monument, but a tiny, ubiquitous QR code. While parts of the world are still fumbling for exact change at the cafe, a viral video is proving that India's decade-old Unified Payments Interface (UPI) is the ultimate culture shock for visiting Europeans.

Taking to Instagram, on the 10th anniversary of UPI, Manika - a content creator 'helping French travellers discover the real India' - shared her sheer amazement at the deep integration of cashless payments across all levels of the Indian economy.

While she was aware of UPI before her travels, she said the on-ground reality of scanning QR codes for everyday micro-transactions left her stunned.

"O...