First the OA has 4 questions (1 easy, 2 med, 1 hard) with a short time period around an hour and a half. Answering >3.25 questions is usually enough to progress. If you pass the OA, you are invited to the Power Day which is 3 interviews (1 hour each) with an hour break. The Technical interview was an OOP/Class Design question (Leetcode Easy) and the next question was a Leetcode Medium/Hard related to Linked Lists. The Behavioral was a pretty standard interview with 3 "tell me about a time when..." questions, but be prepared to answer a TON of follow up questions. Lastly, the Case Interview was not necessarily difficult but unique involving a specific problem experienced to Capital One and it involved a lot of data analysis / coming up with an efficient approach to implement the analysis in code. I would say that the most important thing is even if you have difficulty with a certain part, to always keep communicating with your interviewer.