I was invited by a recruiter to an all-day in-person college hiring event in Seattle. The interview was for a full-time position six months out following my graduation. I did not have to participate in a phone screen. About 50 people attended my session, and the interview took place over 4-5 hours. We solved interview problems in small groups, but each candidate's success was not contingent on (or competing with) the success of other group members.
We were seated in a large, well lit room, in groups of 3-4 people, and each provided laptops and whiteboards. Each group was given a folder of three related programming sub-problems, each one to be selected for one group member to complete. The problems were related to each other so that group members could collaborate and share notes, however as individual candidates we were only responsible for solving the chosen sub-problem.
For the main part of the interview were instructed to open an IDE on the laptop, with access to a partially completed Java library, and to implement a given function as specified in the problem statement. At any time a solution could be evaluated against unit tests for correctness. We were given two programming sessions of ~2 hours each, with lunch in between. The interviewers visited with each candidate for brief one-one-ones during this time, to answer questions and probe problem-solving skills. I felt like I was given enough time to develop a correct solution, with an extra round for revision, before submitting my code. I thought the programming question was not too difficult for a senior with Java experience, given the time and resources we had to solve it.
At the end of the day, we had a Q&A with a few SDEs from different teams and tenures at Amazon. Overall the college interview was a positive experience.