One word describes this process - stringent, and not necessarily in a good way. While I can appreciate that this company hires top tier people, I firmly believe Capital One is missing out on a great amount of high-performing, high potential candidates.
There are 4 steps - phone screen, testing, phone interview, and onsite interview. Of these, I think the testing is the part that really eliminates potentially good candidates. The testing is designed to determine a candidate's success level within their environment; however, the way the questions are worded (specifically for the verbal assessment), they are designed to trip you up. Think of it like an ACT or SAT test on steroids.
Unfortunately, I didn't make it past the testing stage, and there are no exceptions. If you don't pass that, you're done. Personally, I am anti-assessment as a tool used in the selection process. I don't feel it adequately captures a person's ability to flex and adapt in a job or the work environment. If a company lets a tool make their decisions, then they certainly aren't deserving of the candidates they let slip through that process.