High Performance Mobile App Development

Hi, I want to develop high performance mobile application for e-commerce, Grocery Store... 1. It should be high performance 2. Easy to use buy customers and attractive UX/UI 3. Email/SMS/Tracking/Customer Location Navigation/Filter/Sorting /Search Products/ etc.. will discuss each functionality in depth 4. Payment Gateway,.. 5. Admin : Order , customers, Inventory etc.. details would be in demo or in features documents 6. Concurrency Management 7. GST Enables Billing format to customer 8. Customer Preferences, choice , liked products dynamically displayed : need more analytics on customer frequent orders, products choices... etc and many more.. Development: 1. Agile way of working is must for the product developments. 2. daily or alternate day demo. 3. Product will be developed in the phases / milestones so the payment will be released only after completion of the features of the milestone and after handover the expected , tested milestone source code to me. 4. Each milestone features will be deployed in the live environment. 5. Freelancer has to give full support in the deployment and integration of source code in my local machine and then to be moved immediately to the production environment/Live at each milestone Technology: framework 1. Xamarin (Mostly preferred) 2. Cordova MongoDB MySQL SQLite Hosting: Cloud VPS/Dedicated .. will discuss on the framework and technologies over the chat in freelancer.