An internal recruiter contacted me on LinkedIn regarding this position. He asked me some basic questions over the phone before arranging a second phone interview with the hiring manager. I was then invited to an on-site interview with two engineers.
The first one had some technical questions that weren't too difficult. However, the second interviewer's questions were much more challenging and not unlike what you'd see on a computer science final. Despite the difficulty of the interview, the main recruiter told me I had "survived" and that the company would be sending me a coding test.
But two days after that, she sent me an e-mail saying the company had decided not to move forward with my application after all. It was definitely very puzzling.