Are old (>35) faculty candidates discriminated against all over the world? I think that in India research institutes will never take a faculty candidate who is over 35. Is it so all over the world? 

I am asking this question from the point of view of if someone starts their PhD. at the age of 27 then its unlikely they will be faculty candidates till they are 40.
Absolutely not.

Age discrimination is explicitly illegal in the US.  (I believe the same is true in Canada and most European countries.)  Even as the chair of my department's recruiting committee, I am forbidden to ask the age of any applicant.

If you're worried, just don't put your date of birth on your CV.  But this really is a non-issue.