Applied online and did a SJT, small numerical test, and personality test all in one. I then got an email 1 week later telling me I got an interview. They asked me to do a SHL numerical test online (which is not too difficult if you practice beforehand) and then I had 3 weeks to prepare for the interview. The interview is 3x30mins (3 different interviewers). Their decision to hire you will be almost entirely based on your ability to answer behavioral questions. Each behavioral question they ask will be related to one of Amazon's 14 Leadership Principles and each interviewer will focus on 2 LPs. My advice would be to know Amazon's LPs inside out and prepare 10 -14 cases from work experience or university that could be used to answer behavioral questions. Each case/scenario you prepare should be applicable to at least 2 LPs and your answers should be 2-3 mins long. Must use the STAR format. Focus on LPs that are more relevant to your role (e.g. Frugality and "Hire and Develop the Best" are not asked very often). Check out Dan Croitor on YouTube - he has some good Amazon interview videos. Lastly, give yourself plenty of time to practice the cases you prepared. I practiced mine every day for 10 days before the interview, often preparing with friends and family, and I had success in the end.

Star Method and Leadership Principles. Just study these from the materials they give you, and form a story for each principle, and when they ask questions, you can see which principle they are asking about.