I've done OA from Amazn for Junior Software Developer position. There were 2 coding task and each task has sub-task, where you should describe your solution and write time complexity. Afterall, I was asked to complete work-style assesment. It has been taking approxiamately for 15 minutes.
The firt coding task is https://leetcode.com/problems/k-closest-points-to-origin/
The scond task has similiar structure and description as in this link https://leetcode.com/discuss/interview-question/823550/amazon-oa-2020-optimize-memory-usage. I took photos of second task.