Crypto wallet, web and app. Technology for front end is React, react native

Looking for a blockchain developer to integrate a blockchain wallet on a project we are into start building soon. we want to discuss details accordingly so we start from the right path. we have decided to choose react for frontEnd and Python for Backend. The app would have its own crypto currency which will be used in the app as a payment method and an exchange to other payment gate ways. the developer must have previous experience with smart contracts and wallets development.