title: good practice: REST API as the interface between the interface layer and business layer?
body: <p>I was thinking about the architecture of a web application that I am planning on building and I found myself thinking a lot about a core part of the application. Since I will want to create, for example, an android application to access it, I was already thinking about having an API.</p>
  
  <p>Given the fact that I will want to have an external API to my application from day one, is it a good idea to use that API as an interface between the interface layer (web) and the business layer of my application? This means that even the main interface of my application would access the data through the API. What are the downsides of this approach? performance?</p>
  
  <p>In more general terms, if one is building a web application that is likely to need to be accessed in different ways, <strong>is it a good architectural design to have an API (web service) as the interface between the interface layer and business layer</strong>? Is REST a good "tool" for that?</p>