Eh... sometimes? But, honestly, that's not an assumption that should be made... you need to be fluid enough to handle it all. Even in the Theoretically Standardized codebases, different approaches and styles come and go according to the fad du jour.

Right now I have to deal with 3 codebases on a regular basis, in three-four languages, written partially by people not even here, over the past 5 years. On a bad week, I have to crack open 3-4 more codebases in 2-3 more languages... and don't even get me started on reading open source code.

If I am looking for predictability, I'm going to be disappointed, and if I need it, I'm going to fail. Grok it is what I say.