Amazon's OA has parts: coding and a work style assessment.
The coding section gives you problems in minutes. Expect LeetCode medium difficulty. Your code runs against hidden test cases and gets scored on correctness + efficiency.
The work style assessment asks about scenario-based questions mapping to Leadership Principles. There are no right answers, but contradictory responses raise flags. Answer consistently.
About - of candidates pass the OA. If you fail, you can reapply after months.