Being a front-end developer is a relatively broad term, because there are a lot of different services that are under the giant umbrella of being a front-end developer. Usually, a developer has several different services that they are an expert at, and an agency has lots of different services.
Then, an agency has a lot of these experts and they come together to offer pretty much every service that would classify as front-end. I have included several of the main areas that fall under the category as front-end.
Basically, the major thing that comes from front-end developers is web design. They are professionals of making web pages the most functional that they can be, all while making them visually pleasing and aesthetic to the eye.
They also are responsible for making the web design very responsive and optimized for smartphones, because more and more website traffic is done from smartphones every year.
UX prototyping is offered by agencies like http://www.aspirity.com/, and it is very useful in the world of startups and getting new companies off the ground with investors. A front-end development agency could basically create a mockup of your ideal software so that you can pitch it to investors of your company.
It is not worth the investment in most cases to build out the entire software because you do not know how it will play out, so it is smart to hire a front-end developer to build an interactive prototype for showcasing your idea.
Redesigning UI and UX
If you think that redesigning the user interface of your existing software, a front-end developer would make for a great consultant in the process. Many agencies that focus on this are busy because it makes sense for a company to constantly look for ways to innovate.
Instead of building a completely new software, it makes sense to see what kind of options are out there for your software and see if it would be worth pursuing.
I know that this post is focused on what a front-end developer does, but you would be surprised that most agencies with front-end developers also are experienced with the back-end side of things.
In my opinion, it makes sense to find an agency that specializes in both because it is less friction from two agencies working on your website or software, and it simplifies the whole entire process by using an agency that can do it all for you.
Back-end development deals more with function ability and the backbone of whatever you are trying to build. If you shop around it is pretty easy to find agencies that are experienced and have a great track record in both back-end and front-end.
Those are just some of the main services that are offered by front-end developers and their agencies, but there are other services that were not mentioned. If you feel like this post helped you gain any knowledge, then please go ahead and share it with someone else!