American office English treats careful analysis as a separate event.
deep dive — “an exhaustive investigation, study, or analysis of a question or topic.” It is recorded from 1986. It is usually put on the calendar: “Let’s do a deep dive on that next week.”
get to the bottom of it — find the real cause.
take a step back — stop working on the solution and look at the problem again.
what problem are we solving? — a question asked when a discussion has moved ahead of the problem.