"Product designers manage the design and development of all kinds of products across many different industries. Employers are looking for bright minded individuals with a passion for innovation and problem solving. To showcase these traits, go to an interview prepared to give examples of successful projects you have worked on in the past and answer some case studies on how you would approach designing hypothetical products."
Design an interface for a rail station ticket booth
There are a number of constraints you should make sure you understand before diving in. Really more an assessment of your thought process than the final design.