McMaster-Carr interview questions

I had 3 calls total. First call: 30 mins, Recruiter, more of an intro to the company, not many questions asked about me, other than logistical ones. Second call: 30-40 minutes with the recruiter again. This time, they asked questions about my experience, pretty general behavioural interview questions. Third call: 45 min call with a lead engineer/manager. It was extremely open-ended. During the second call, they informed me I would be talking about a previous project, and to have metrics ready. The interview was more like me talking the whole time about why my project was interesting and what made it technically complex. I didn't get past the 3rd call, but I was told there is a 4th full day of onsite interviews after that. I would study up on an adequately complex project and be prepared to talk about it at length.