I didn't get as much exposure to the rest of the company as parent comment, but I'll say I saw a weird air of complacency and assumed success.
I first ignored my instincts that something was wrong, but as I saw more of how the company operated, I became convinced that the single largest problem the company had was the culture. On the surface, I agree with the parent comment, things were definitely positive, but rather than toxic, I think it was more of a naive one, like most of these people had never worked at a startup before, and didn't understand that it's always easy to snatch defeat from the jaws of victory, and that if they didn't understand what they were doing and how it affected the company then probably nobody else did either. It felt like everyone was very smart, but somewhat foolish (myself included).
That being said, I enjoyed my time there, and definitely learned a lot, especially organizationally. The people are solid and I think Affirm is going to get a pretty sweet deal.