Every codebase is a Ship of Theseus.

Replace a function. Then the module. Then the architecture. At what point does it become something else? Nobody has a principled answer. The interesting zone is 1–99%, which is always where real codebases live. A continuous spectrum with a discontinuous social meaning.

But code leaves traces.

Comments are the most honest writing a programmer produces. Nobody writes them to be read. No one's performing for an audience. "fix," "wip," "ugh," "finally." Involuntary poetry. Sometimes a comment meant to be temporary survives everything around it, pointing at a room that no longer exists.

finds them.