Pros
If your number one priority is career, Qualtrics is a great place for you to work. There are super interesting problems to solve. Qualtrics is doing amazing things in Engineering that very few (if any) other tech companies are even trying to tackle. The people you work with are super smart and you can learn a lot from them. The trajectory of the company is great, and it you can hang on to the 'rocket ship', I do believe that it's going places.
Cons
"Work hard, play hard" is the claimed motto, but the play hard part has kind of gone away in recent months, at least in Engineering. Engineers are generally expected to work crazy long hours, and on top of that, remain available all hours of the day/night/weekend in case of 'incidents'. Even when I wasn't at work, I couldn't relax. I was always worried about when the phone might ring. (If I could give work/life balance a 0 I probably would.) This wouldn't be so bad if the pay were near the top of the market, but it's not. It's middling at best. The culture has shifted in the last year or so. When I started a few years ago, everybody was pretty happy with the situation. Sure, things were still busy, but it was more driven by what we wanted to build rather than what we were told to build. It seems like the culture is shifting towards an Amazon style of Engineering department (based on what I've heard, anyway): employees are a resource to be consumed and discarded. I'm hoping that management is just mostly unaware of the morale issues in Engineering. If they are aware, they're just ignoring the problem, which in a lot of ways is worse.