I saw a Facebook ad for the position in November, 2016. I submitted a resume + cover letter online in late December. I heard back from a recruiter a couple of weeks later, who set up a phone interview with a team member a few days later.
The phone interview was a very introductory screening - it's not a full-fledged interview. others have said, they do a riddle, but it REALLY isn't about whaAfter that, I got a job test that tests logical thinking and some of the most basic responsibilities of the job. It really is just to see if you would like and be good at this kind of work. Despite what some people have suspected in reviews, they won't co-opt your work. If you get the job test and think that that might happen, you probably don't understand the job that well.
A couple of days after the job test, they held another phone interview with my potential supervisor to dissect the job test and ask additional questions. After that, they offered me the chance to fly down there to do an in-person final interview, but the timing didn't work and I did a Skype interview instead. The final interview was done in stages with various team members and more senior supervisors. After a reference check, I got an offer and accepted.
The process was smooth and professional. If it seem weird that they're constantly soliciting feedback on the process, that's just the way they are. You should apply if this sounds like your kind of job!