Amazon Vendor Manager interview questions

This interview was obtained through a recruiter and the position was based in Seattle. Amazon did not have any suitable candidates in the pipeline and after the recruiter submitted my resume along with 1/2 a dozen others, only mine was chosen for an interview. Later, another candidate was "brought back from the no pile", to ensure a competitive process which Amazon prefers. The first 1 hr phone interview was with a peer, as all Amazon employees are asked to interview candidates for similar positions from time to time. A week later, the second 1 hr phone interview took place with the hiring manager. Typically, after passing these stages, successful candidates would be invited to Seattle to meet in person. However, this specific posting required a unique skill set, for which Amazon only had one subject matter expert currently employed. Therefore, another 1 hr phone interview took place with the subject matter expert. After passing this, I was certain an invitation to the office would follow, but both myself and the other candidate were asked to submit a written piece on the specialized subject matter. Making sure that external experts had reviewed my work prior and after submitting, it took me 3 days to put together a very professional document. This stage took another week to process and revert, resulting in the other candidate not being selected to continue. At that point, I was the only candidate left, with no other prospects in the pipeline after a month of phone interviewing. A week later I also got the notice that my candidacy was not being pursued with a final comment of "we have a no feedback policy".