I will have to admit something here first. I am not a "front end web developer" in the sense that I do not have anything beyond a working knowledge of HTML, CSS, JavaScript, and (increasingly importantly) jQuery. The web programming I do is typically with server-side controls and code behind in C#. As such, I do not personally have much call for consuming data that is not "natively" .NET, or which Visual Studio .NET abstracts away from me with references and proxy classes.
But I have witnessed wizards in jQuery, who have little to no knowledge of SharePoint or its object model, directly consume SharePoint data and the result is sheer UI magic. In fact, the UI platform may not even be Microsoft – nor need it be. These developers only ask that you provide the data in an "industry standard" format such as ATOM. And then query that data using industry standard REST. REST stands for Representational State Transfer and what it means is a query...