MarkLogic Senior QA Engineer interview questions

I received a call from one of their recruiters/HR. Had a phone interview with her where she asked me some basic technical questions and some general behaviour questions. After that, she setup a phone interview with the hiring manager. Talked with the hiring manager where she asked a lot of questions related to day to day activities of a QA engineer and at the end she emailed me a so called homework which consisted of installing their XML server and writing some scripts to retrieve information from the server. After I finished the homework, I had a 1:1 interview with several members of the company (QA engineer, VP of people, QA Manager). They asked all kind of questions, from very technical questions to how to deal with specific problems or how to solve or test a specific type of system. Once you pass that interview, they call you back for another interview with more technical people. They claim they hire only the smartest people, but after talking with several individuals, I don't see how they can make that claim. Out of the eight people I talked with, only two of them impressed me. The rest did not show any signs of being any smarter than the average engineer.