Apple Pay | issuing | merchant integration | REST API | mobile UI/UX | architecture | data processing | payment processing | funding | Fintech | web framework | QR-based payment | merchant service | e-wallet | blockchain | communication | strategy | product management | payment Apple Pay | issuing | merchant integration | REST API | mobile UI/UX | architecture | data processing | payment processing | funding | Fintech | web framework | QR-based payment | merchant service | e-wallet | blockchain | communication | strategy | product management | payment