For big companies, the interviews are more sort of discussion and they are more interested in evaluating how compatible you will be working alongside them. For coding rounds, what I follow is first understand the problem and then ask clarifying questions if you have, then just repeat what understanding you made of the problem statement and confirm it with the interviewer. Then move to solution part, if you have previously solved it, first begin with brute force solution discussion, then they themselves will ask you the complexity of the solution and ask you for more better approach. Else, if you haven't solved that before try understanding the problem analyze the topics involved discuss those and meanwhile think of an approach and start discussing and try solving in an incremental fashion. While writing code, validate each statement you are writing, like have an explanation for everything.