I applied months ago and was skeptical of their process. Their filter is a take-home test involving a code review and a simple algorithm problem. Neither is particularly hard, but I did poorly because I didn't realize they were grading it on a point-system by comparing it to an answer key. If you have a typo or do something differently than their key, you lose points. Lose a few points and you're out.
Honestly, it reminded me of someone trying to hire an author by giving them a spelling test.