| Challenge | Solution | |-----------|----------| | – static VPAs per merchant quickly hit “duplicate” errors on NPCI side. | Introduced dynamic per‑order VPA generation using the upi://pay schema with a unique suffix (e.g., order12345@faphouse ). | | Callback Latency – occasional 5‑second delay from NPCI during peak periods. | Added Kafka buffer and out‑of‑order handling; UI shows “Processing…” but auto‑confirms once event is consumed. | | Bank‑Specific Error Codes (e.g., UTR_NOT_FOUND ). | Normalised to a common error taxonomy ( PAYMENT_DECLINED , INSUFFICIENT_FUNDS , BANK_TIMEOUT ) and surfaced friendly messages. | | Device Compatibility – older Android devices lacking Intent handling. | Fallback to QR‑code scanning plus an in‑app mini‑UPI SDK that leverages the UPI SDK from NPCI (available on API 23+). | | Regulatory Change – RBI’s 2024 cap on collect ‑type transactions for new merchants. | Built a dynamic rule engine that toggles between collect and request‑to‑pay based on merchant KYC status. |

FapHouse functions as a subscription-based platform. Unlike localized services like YouTube Premium or Netflix India, which have integrated UPI, FapHouse mainly supports: : Visa, MasterCard, and American Express.

: During checkout, the user selects "UPI," enters their Virtual Payment Address (VPA) (e.g., username@bank), and approves the request in their UPI app (like Google Pay or PhonePe).