Amazon

Extremely hard and requires extensive preparation. You need to get yourself fully committed to Amazon's Leadership Principles and work on scenarios for each of them. Basically, create a matrix of scenarios and answers.

Phone interview and 5 loop interviews. Can't describe anything; the experience depends on the interviewer. Some interviewers make you feel good, but some interviewers ask tough behavioral questions.

I applied online. The process took 2 weeks. 2 back-to-back interviews with behavioral questions and some questions about cloud and web stack. Overall the interviewers were very nice and friendly, if you know the basics you should be good.