Do you know how Apple’s app switching ability works? How it can look like magic when you go from one application to another instantly? They save a screenshot of every app when it closes. When you start the app back up, the first thing that happens is that the OS shows the user that screenshot, after a zoom/fade animation. This looks to the user like the app actually starting, but what they’ve really done is buy themselves several seconds of load time. You’ll only ever catch it if the app is extra-slow starting, and you realise that you can’t do anything even though it looks like you’re ready to go.

This is the world where User Experience (UX) and User Interface (UI) meet, and it is the magical formula developers and designers use to make you love their creations.

The area of shared expertise between the two roles includes knowledge of UI patterns and standards—the widgets and elements that make up a user interface – as well as knowledge about the software development process.

The following are very simplified descriptions of the roles associated with UI Developers and UX Designers.

UI Developer – One who builds user interfaces that support the exchange of information between an application’s users and its back-end processes and databases. This could be either a fully dedicated role on a development team or a hat a developer who is also responsible for coding the back-end processes might wear. A UI Developer’s output is functional, testable, shippable code that lets users accomplish their goals when using an application. The UI Developer is also responsible for documentation that allows others to maintain their code.

UX Designer – One who designs the user experience for applications after doing user and workflow analysis, producing user-cantered design artefacts such as personas, site maps, taxonomies, and wireframes. An UX Designer may also conduct usability testing on prototypes or finished products to assess the quality of a user experience.

If you ask a UX Designer and a UI Developer who is the principal designer of the user experience, expect to hear a resounding “I am!” from both of them. This is where the problem kicks in often, the blurred line between functionality and beauty, usability and aesthetics. As essential as both opinions are in the process of creating a great product, there needs to be a fundamentally understood balance between the two, because ultimately it is about the user and the experience they will have using the website, application, etc.

Fantastic user interfaces come from maintaining a fine line between the two disciplines. So the next time you use a website or an application, think about the work that went into the look and feel, there is a lot done behind the scenes to make your experience as effortless as possible.