[1474295912]

I wonder what percent of these questions in all the 5 rounds have production level significance? Do people really solve these "Invert a red-black tree" problems regularly at their day jobs?

I understand Big4 doing this as they're bombarded by resumés, but the problem starts when mom'n Pop CRuD shops start aping these blindly.

[collyw]

Exactly. The only time I have needed to implement a quick sort was for university exams or interviews. The rest of the time, pick an appropriate library.

[gaylemcd]

No, and people don't really ask that interviews. (Or if they do, they shouldn't.)

The point of these questions is basically to assess intelligence (as it relates to coding). It's not about having you solve a specific problem because you might need to solve that exact thing in the real world.

You're right though that part of the issue is a bunch of companies trying to replicate the Google process (which might not even be right for their company) -- and then not knowing what it's all about. So they ask super common or really easy problem, which don't even test problem solving skills.