Back-end Web Developers are responsible for server-side web application and integration of the work front-end web developers do. They will write web services and APIs used by front-end developers. Working closely with marketing and design functions they will use test sites to see which ideas best suit the brief.
Using reliable code, they will build the framework considering UI, cross-browser compatibility, general web functions and standards.
A Web Developer will need a good understanding of server-side CSS preprocessors, accessibility and security compliance as well as authentication between multiple systems and servers.
With the growing use of tablets and smartphones, it is essential for a Web Developer to understand the differences between mobile vs desktop platforms.