One of my clients has me looking a fairly complex mod_perl application that has several dozen modules arranged to varying degrees in object heirarchies. There are several examples of empty subclasses that exist to as aliases for their parents. There are very nice examples of method overriding whose purpose isn't entirely until the parent class is examined. Of course being a mod_perl app, one can't fire up the debugger and trace a live program's execution. Still, I think I've done pretty well at understanding this byzantine code.
Can I list the following skill on my résumé:
can stick his head up the ass of any perl code base
I think so.