Your prospective user-interface designer should feel comfortable answering this question, mainly because both UX and UI designers are DESIGN focused, so quite OFTEN they understand each other without much explanation.

When UI designers need to adjust, change, add or remove something PROVIDED by UX designer, they should focus their communication on wireframes, UI elements, personas and on how it will affect the entire user journey. UI and UX designers should ALSO test the PRODUCT and give feedback to the developer during development stages.

Your prospective user-interface designer should feel comfortable answering this question, mainly because both UX and UI designers are design focused, so quite often they understand each other without much explanation.

When UI designers need to adjust, change, add or remove something provided by UX designer, they should focus their communication on wireframes, UI elements, personas and on how it will affect the entire user journey. UI and UX designers should also test the product and give feedback to the developer during development stages.