I walk-in interviewed for a job at amazon fulfillment center during peak season (Late November 2017) and basically got hired the same day pending drug test/background. They had me fill out a ton of disagree-agree likert scale questions as well as what type of job/hours you'd be interested in. There were a few assessments to take just gauging responsibility, work ethic, punctuality, situational questions, (are you gonna steal our stuff?) etc. Apparently you can take them online in advance. I'd strongly recommend that because if there are a lot of people in line waiting you'll want to get through the process and out asap.
Then after that you have to sit and watch an introductory video loop at least 3 times. They'll pull you aside to take a picture for the employee id, ask some simple questions about tax, disability, veteran status. Asked what shift I want out of the ones available and direct hire, temp, etc. No real interview. Drug test (oral) and background check. I was given the date for the next orientation. Then the next week after that you'll start.