Interviewing is totally broken.

The people you are looking for will never come in for an interview, unless it's a major position like lead engineer or your compensation is off the charts. I am a fairly new programmer and have had numerous job offers without an interview. I would say I get two or three job offers a month, usually from fellow coders I am working with.

If I were hiring, I would skip the coding challenges (unless it's for an entry job and you have 100 applicants).

In the end, what you really want to know is:

Are you humble? How fast do you learn? Would you fit our culture? Why do you want to work here? (or how long)

Unfortunately, it's hard to know you are getting an honest answer. What you really need is a recommendation from other programmers in your office.