I had two rounds with Uber ATG self driving team interview.
Each round took an hour long. The interviewing process is tough.
I have 5 mins to introduce myself and go directly to coding part.
Uber use code pair on phone interviews. Each round has two questions.

1st round:

• https://leetcode.com/problems/shortest-word-distance-ii (premium)
• https://leetcode.com/problems/meeting-rooms-ii (premium)

2nd round:

• https://leetcode.com/problems/word-search-ii
• https://leetcode.com/problems/sliding-window-maximum

Time is really really tight. I finished the coding near to the end of clock.
Have to explain time and space complexity and design your own test case.
Do not forget corner cases with inputs.

Feed backs from HR: you can always ask the recuriter about your interviewer's feed back. The first round I got a 3/4 since the interviewer did not like my naming of variables. He gave me the problem in python, I have to write it with C++, thus, I missed his naming details and rushed into solving the questions.
The second round, I got a 4/4. The interviewer did not leave any feed back for improvement.

Onsite interview (5 rounds):

1st round: [Manager]

• Starting with self introductions and then directly goes to my research area (I got a Ph.D). Explain the research to him (15 min). Then the rest are all BQs. Easy round.

2nd round: [Another manager]

• Behavioural questions.
• Design google auto compelete system in very detail. From user search to Trie update. Database to aggregator, ML algorithms to mapreduce. You name it. If your system design sill is rusty, you will be toasted througoutly.

3rd round: [Bar raiser]

• Basically pure SDE related behavioural questions.

4th round:

• Design social network network graph, and quering system.

5th round:

• https://leetcode.com/problems/insert-delete-getrandom-o1

I don't like the way the arrange the interview. I would prefer to have those algorithm questions and design questions in the beginning instead of pushing them to the end. In the 5th round, I was in a dummy status already.
I solved that question a few times on leetcode, however, I did not give the correct answer in the interview due to my mental and physical limitation. Feels bad.

Hope this post can help you prepare. Good luck to all of you guys.

Result: Rejection
All the design questions asked are very very detailed. If not well prepared, then will get toasted thoroughly. I practiced two times on google auto complete system, And even watched 2 videos of how to design that, but those videos are still to shallow to answer the interview question. They failed me today. Feed back is: my coding and problem solving skills are strong. However, need improvement on architecture skills. Should contribute on open source projects and get experience to improve the skill, and of course, freeze 6 month.