Mobile App Developer Needed for backend changes in payment gateway integrations

I’m looking for an experienced Flutter mobile app developer to make backend level changes required for a smooth PayFast payment gateway integration in an existing application. The ideal candidate should understand existing app architecture, APIs, and payment flows, and be able to implement secure, reliable backend updates that ensure seamless transaction handling. You will work closely with me to align the integration with the current app logic and business requirements. If you have hands on experience with Flutter, backend integrations, and payment gateways, I would be glad to connect.