Front-end developer creates client-side web interface using HTML, CSS, JavaScript and other common client-side technologies. The FE developer sees pages as a whole and a website as a combination of those pages. They make sure that the website functions properly, like all the website elements.
UI-Developer also uses HTML, CSS, JavaScript, jQuery, Angular, React JS and other client-side technologies. For UI developers, more emphasis is on HTML and CSS. Their focus is on delivering more granular assets such as buttons, tooltips, and other modular pieces which will go into a larger, finished product.
The developer sees an asset as the individual CSS styles and pays more attention to how the asset will look, feel, behave in different contexts. UI developers may not even see a website as a whole but rather a collection of assets applied to pages. The UI developer makes sure that everything on the site is user-friendly and looks good.
