Fullstack dev needed to build a server for a meetup app

We're looking for an expert full stack developer who will develop a social app designed to auto-match users in Copenhagen to meetup. We have already developed a backend system and would like to see if we can either reuse it or if starting anew is needed. The full stack developer must be proficient in: - Unity - C# - MySQL - PhP - AWS - iOS/Andriod Please view the images attached to get a basic reference of our product and workflow.