Capital One Sr Software Engineer interview questions

I applied online on 12/30/2020. First week of January 2021, I got the call from recruiter and we had general chat about my background, education, experience and also recruiter explained me about role, location and work culture. After this call, recruiter sent me HackerRank coding test. It had two coding questions and I got 8 hours to complete. I was able to complete both coding test within 2 hours. All test cases were passed, code compiled and submitted. NOTE: It is very important to pass all test cases. Within a two weeks of HackerRank coding exercise, Capital One decided to move forward for further interviews. I was scheduled to attend PowerDay interviews - 4 rounds of interviews. Due to COVID-19, it was conducted virtually. Each round of interview was lasted for 45 minutes. Round-1 - Technical Coding Interviews. During this round, Interviewer asked me to code with my favorite programming language. Interviewer asked me - Given array, find two elements of array whose sum is closest to zero. It was pretty straight forward problem and I was able to code it. After that interviewer asked me to improve code for better time complexity. Before I complete coding, time was already up and interviewer decided to go for Q&A. Round-2 - System Design, Debugging, Analysis interview During this round, Interviewer asked me to design system to add employee information, like name, etc. Then Interviewer asked me questions on various debugging skills. If there is an OutOfMemory issue in system then how will I handle and triage this issue etc. Round-3 - Behavioral Questions During this round, I was asked several Behavioral questions and I answered then using STAR approach. Pretty simple and based on day to day work scenario. Round-4 - Case Interview During this interview, Interviewer provided me case - Capital One recently acquired another online bank so what will be the benefits for Capital One from business and technical perspective. I discussed entire case with Interview from business and technical perspective. Within two days of PowerDay interview I got the call from recruiter that Capital One is willing to offer me job. Recruiter scheduled my interview with actual hiring manager. It was pretty 30 minutes call to know each other and team environment at Capital One. After the interview with Hiring Manger, I got the offer letter within a day and then background checks kicked off. Entire interview process was seamless and hassle free. I also had interview with Amazon during same time period I was interviewing with Capital One but I like the Capital One interview process.