Developers usually come in one of two major categories: front-end and back-end. Both are necessary to any functioning digital project, and they have to work seamlessly together to create a product that achieves its full potential. 

But the skill sets and approach a front-end developer must bring to a project can differ wildly from those a back-end developer supplies, and vice versa. Trust us, as the software developers for some of the biggest names around in tech, we know.

Here are the differences between front-end and back-end developers that our clients most often ask about and need to know.

What does a front-end developer do?

The front end of an application is, in a nutshell, the part of an application the user sees. It’s a front-end developer’s job to make sure everything that makes up the front end works together perfectly. In particular, they need to ensure user interactions go through and any information users need to view gets displayed without any hitches. They’re the ones who work with the application fonts, graphics, menus and layouts, and when we work on front-end projects for clients, we ensure that the developers we assign to these roles are the top of the field in these categories.

Take the example of an application for an automated teller machine. The front end is the part of the software that the bank customer interacts with: It asks for her ATM card, lets her input her PIN, gives her a series of options to check her bank balance, withdraw cash or deposit checks, and finally reminds her not to forget her ATM card when she’s done.

What does a back-end developer do?

The user never sees the back end of an application. However, the back end (which includes the software structure, API, logic and data applications) does the bulk of an application’s actual work. If the front end’s the tip of the iceberg that juts out over the surface, the back end’s the bulk of the iceberg, concealed but incredibly substantial (as any careless luxury passenger liner can attest). When we assign our developers to back-end work, they have to be our best experts in structure, data, logic and APIs.

In the case of our ATM program, the back end is the part that reads the bank customer’s ATM card and looks up her ID and accounts, checks the PIN she enters against the one on file and accesses the bank databases to tell her how much money she has in her savings and checking accounts. It interacts with the bank’s financial servers to convert the requested amount into cash, then coordinates with the automated cash dispenser in the bottom of the ATM to give her the correct amounts in the right assortment of bills. It also coordinates with the bank’s security software to flag suspicious activity, letting the bank’s security department know there’s potential fraud or worse at play. When the user session is over, it’s the back-end software’s job to tell the machine to activate the card reader to return it — or to tell it to hold and safekeep the card if it determined that the activity was potentially criminal.

What skills does a front-end developer need?

Our front-end developers have deep experience in UX and UI design, including front-end programming languages like JavaScript, HTML and CSS; as well as JavaScript frameworks and libraries including Angular and React. They likely know text-editing tools (like Notepad) as well. Because the front ends of tech projects have become increasingly dependent on graphics, familiarity with programs like Photoshop is a decided plus. 

What skills does a back-end developer need?

Our back-end developers possess the ability to create code that can handle all of an application’s operations and data and, of course, operate in sync with the front end. They need to be well-versed in programming languages like Python and Java, as well as database tools like SQL or Oracle PL/SQL and helpful programming platforms like PHP frameworks. They’ll often be the ones responsible for keeping the software running in the future, so version control software and debugging tools and procedures are always be part of our back-end developers’ repertoires.

Do I need a front-end developer or back-end developer? Or both?

If you want to perfect your customers’ user experience and ensure they can access your services smoothly, you want a front-end specialist. If you need someone to develop the meat of your application, the all-important processes that the user never sees but that store and access data, communicate with your servers or the cloud, or that do the “thinking” behind the app, then what you need is a back-end specialist. In many cases, clients need both, since both the front end and the back end have to be written, in place and working in lockstep before a tech project can launch.