I’m building a complete payment gateway that must run smoothly on iOS, Android and the Web. Users and merchants have to be able to pay or get paid with the following methods from day one: • Credit and debit cards • Direct bank transfers • Digital wallets (Apple Pay, Google Pay, etc.) • USDT stable-coin Security is non-negotiable. Every account and transaction has to be protected by two-factor authentication, and the system must include real-time fraud-detection logic that can be reviewed and tuned from an admin panel. What I expect to receive: • Production-ready mobile apps and a responsive web portal • A clean, well-documented API layer so third-party sites can plug in easily • Merchant dashboard with reporting, settlement tracking and role-based access • Source code, build instructions and basic unit tests Please keep the architecture modular so that additional payment rails or extra security layers (encryption at rest, tokenisation, etc.) can be dropped in later without a full re-write.