Public code repositories are the first place I go when I look at applicants.

Surprisingly, however, public code rarely tells you anything about a user's CS fundamentals. Can they tell me the time complexity of a method they just wrote? Do they know the difference between a depth first and breadth first search?

I've met individuals with good code who were unable to answer CS 101 level questions like that. It's not a deal breaker, but it needs to be given some weight and consideration in hiring. It's also a matter of seniority -- I would never offer a senior developer position to someone who didn't have CS fundamentals because I expect such a person to solve hard problems that fall outside of "hacking up a webapp".