I'm 41 and still have recruiters contacting me and generally do well in interviews. I'm lucky in that the skills I have are harder to find (8 or so years doing iOS development). I also have to admit that one thing that helps me tremendously is that I look young. Just about everyone I work with assumes I am still in my 20s based on my appearance. They all act shocked once they do find out that I'm older. Looking young helps a lot with rapport in interviews since the interviewers feel more at ease that I'm "one of them" rather than some old guy.