They have a multiple step process including: Phone interview, online assessment, and on-site interview. The phone interview is pretty straightforward - they will tell you about the company and their role (they will have someone from the function you applied for call you, not someone from HR). They will ask you about relevant experience, and give you a chance to talk about yourself. They give you plenty of time to ask any questions that you may have, so be sure to have some prepared. They will also ask about other positions that you may be interested in and when you go to interview on site you will interview with people relevant to those positions.
The online assessment is position specific, but everyone gets a computerscience/coding section. I also had a speed math section, a problem solving math section (more standardized test like, but nothing above algebra), and a grammar section. You will have an online proctor via a webcam, so be sure to be in an appropriate place.
If you get invited on site, they actually spend a good amount of time selling the company to you. You will get the chance to speak with several different people relevant to your possible position(s), not all of which are really interviews. Most of the people you talk to are not HR, but people who work in your possible function or related who do interviews/show you around. I had two presentations, one long and one short. The instructions said not to allow time for questions at the end because they would ask questions as you moved along, but I did not get asked a single question until the end of my presentation.