Web application, website & software - Build a backend and a web API

We intend to build a complete backend in order to administrate an innovative platform for social advertising and entertainment for bars, pubs and other kind of clubs. This project requires the ability to create a complete backend, backed by a database, using server side programming languages (and other well known instruments such as CMS); this backend will be responsible for acquiring information about the owners of the establishments (our direct customers) and managing their access (admin side). More specifically we intend to delegate the development of a backend and a restful API through which the services are publicly exposed. At the current state the entire database schema, on which both the backend end the web api will be based, is yet to be defined; The entire project is in an early stage and we intend to investigate the use of various technologies considering the multimedial aspect of this kind of application. In order to reach the completion of the first prototype, the following functionalities are to be developed:  Server side access for admin  Server side access for customers  Admin management over customers  Upload of multimedial contents (only videos for now)  Download of multimedial contents (only videos for now)  Exposure of any CRUD operation (or upload/download) through a web api. We are not interested in very specific proposals, in order to start a project that may considerably evolve over time the following criteria are to be met:  Modularity  Extendibility  Robustness  Correctness  Documentation We are open to consider any choice about languages, platforms, technologies and instruments already developed. The developer/team of the developers will work with our team and according to project specification in which will be explained the data architecture and the client-server communication protocol.