Pretty standard, straightforward process. First: a technical coding Skype interview. If you pass, you'll get second one within a week or two. Second: onsite invitation (a combination of a sell day, culture fit, and one or two technical interviews). The onsite day was great, they flew all of the candidates out and put them in a hotel and reimbursed travel/food expenses. The Provo office is already large and established, and the Seattle office is still relatively small but growing.
Overall, all of the engineers and HR staff I interacted with at Qualtrics were fantastic people. The process was very transparent and timely; the product itself is actually pretty interesting, given that amount of data the company is collecting. Interns have a lot of agency over their projects.