Build a betting/trading website/platform

We need an experienced software architect/developer to help us develop a sports trading/betting platform. Experience in trading/betting required. Main focus should be on: - web-platform pages (landing page with sign in's / main trading platform / account page / back-end page) - html5 platform with sql database programming required - code from previous platform is available and can be utilized. especially around the existing matching engine. - integration of payment system necessary. - mobile app (depending on time ad cost). We can offer pay/hours or a fix sum. Please only bid if you understand the mechanics of betting/trading and how to implement them time critically. Project duration: 4-8 weeks.