They force you to register and apply to a third party site where you can't upload a resume and must manually type out your experience. After a while, they'll send you a coding challenge where you build a simple task list. Using their API. They are unresponsive to questions/concerns. They only care about style. They don't care about code quality, organization, methodology or error handling. In other words, it is a massive waste of time. Don't do it.