IMHO any non-trivial codebase will be awful in some parts. Codebases tell only half the story, and a programmer needs to also inherit the mindset that resulted

IMHO any non-trivial codebase will be awful in some parts. Codebases tell only half the story, and a programmer needs to also inherit the mindset that resulted in the code. Until that happens, there will be a research phase that will result in all the code being triaged multiple times, so the new coders can decide if the piece of code under triage is good, bad, or there's no way to know yet.