I actually don't like the take home problems solution. If I'm currently working somewhere, I really don't want to work on some interview task after hours. I'd rather interview in person, talk about what I've worked on before, go into specifics about my experience, and have the employer trust that the fact I've worked at the places on my resume and am able to explain programming methods as enough to evaluate my competency.

I don't know of any other industry (other than show business) that requires people to audition for a job, especially not engineering fields.