I had 3 separate interviews. In the first interview they asked more about my interpersonal skills such as how you work under pressure and such. They are looking to make sure you understand and know the Amazon Leadership Principles. Incorporating them into your answers indirectly would help. The second interview was explaining your portfolio pieces. They do counter-argue certain design choices you made and they want to know why you choose a certain side bar style, etc. Make sure you know your project inside out, especially if it's a project you did a while ago. Talk about take-a-aways and what you would do differently. Third interview was a design challenge (45 mins to explain your process).