Interviewing.io is a startup that does some research into candidate evaluation. To their credit, they have even posted research with negative results. http://blog.interviewing.io/posts/
Has anyone here done interviews with interviewing.io? How was it, did it lead to a job?
I have a longer reply to a different HN thread with more detail about my experiences here: https://news.ycombinator.com/item?id=11679844