There are many sins in recruiting. One of them is the broad categorisation of developers as front or back-end. But for that a new trend has been emerging and will continue to get stronger, a front-end developer encompasses a lot of skill sets and can't be easily classified.
Traditionally you take a site by getting some HTML, returning it from a server and slapping some HTML, JS and CSS on it. For this you'd expect a front-end developer to be heavily presentation oriented and wield CSS like a mighty sword.
But these days you'll see a lot more apps where the main work is done in the client and the server is just an API to return data (if one exists at all). Yet still developers are broadly placed into a bucket as a "front-end developer". In a world where lots of the logic and presentation is done in the front-end, does that make sense?
Take a good developer who can take data from multiple sources, store and sort it efficiently, test it well and have it accessible in a good API. So, does that describe a task on the front or back-end?
That could just as easily be a developer working on the back-end as a developer working in the front-end. You need to build, or use an existing framework to do all that on the front-end. For that you don't need to do any presentation or CSS work.
So when you think of hiring a "front-end" developer, think more importantly about what you expect that person to be doing: frameworks, presentation, performance, localisation, data... the list goes on.