Ten or fifteen years ago one of the fastest make or break questions I would ask was "what version control system do you use?" (and of course, whether they were

Ten or fifteen years ago one of the fastest make or break questions I would ask was "what version control system do you use?" (and of course, whether they were using nothing(!) or ClearCase or VSS or CVS would immediately say a lot about the culture there); version control is ubiquitous now even in lousy companies, so I think "what is your code review process?" is my new favorite question to get some indicators of the development culture at a company.