Who owns the code?
I found this an interesting read. The article suggests the role of a Code Steward whose job:
is not to safeguard against concurrent-access, but to instead safeguard the integrity+consistency of that code (both conceptually and structurally) and to widely disseminate knowledge and expertise about it to others.
The measure of success, of course, is that the Code Steward's role becomes unnecessary – enabling them to reprise the role on other projects.