I'd say the best thing to prepare for an SE intern role is to do your research. Solutions Engineering is a very company-centric role, so you have to not only look into what the company's mission is but also the lineup of products. When you walk into the interview, you should be able to name and generally explain a few of the company's products. For NetApp specifically, I looked at the website itself as well as third-party videos to help explain some of these intricate technologies. As an SE, it's your role to know these products in-depth to provide support and technical expertise when clients have questions about the product. For the interview, do come prepared with a list of questions as well. Some questions might include inquiries about possible projects that they plan to give interns throughout the summer or something as simple as next steps in the interview process.