Capital One Software Engineer: CodeSignal OA, recruiter screen and a four-round Power Day

I applied to the SE role at Capital One via LinkedIn. The talent acquisition rep reached out and scheduled the OA which was fine, just a normal CodeSignal with 4 DSA questions. I remember being asked Largest Rectangle in a Histogram, a Graph BFS question and a matrix question. They were all easy/medium level. Then I had a recruiter screening which was a regular behavioral interview. They asked me about some points on my resume, how I worked in a team, all stuff that the STAR method is there for. I studied the "Life at Capital One" page as well to help tailor my answers before that round.

Next was the Power Day, 4 rounds in the same day: one System Design, Behavioral, coding and technical business discussion round. The interviewers were all very nice and fair.

The System Design question was to design a banking and payment system similar to Capital One's.

In the technical business discussion, I was given CSVs and charts detailing machine operations. I was asked to calculate the expected running costs, identify business pros and cons, and review a code snippet for parsing the CSV data.

The coding round was a 3-step object-oriented programming (OOP) problem. I was asked to parse data into a data structure of my choice and then write functions to manipulate the data as it would be in a real-world scenario. I also had to explain why my solution was optimal in terms of time and space complexity.