To be fair i won't share the answer here. but for tips, you have to finish your home assignment task and create a slide which you'll use to brief the interviewer on your task. Proactive in asking questions to the interviewer. When you make the slide, make it brief, and make it that the interview get what your intention is and be prepared on fallback plan, your design will definitely be challenged there. Remember that it's all about trade-off in the tech decision making.