How long should a codebase audit take?
The five fast checks take under an hour on most projects. Building a useful map takes one to two days by hand for a medium codebase, or minutes if it can be derived automatically. Reading everything is not a realistic goal and not the objective.
From How to review a codebase you didn't write, published 9 August 2026. That article is where the reasoning behind this answer is set out, including what it does not cover.