As I recall, there are a total of 6 interview steps. I went through the first 2: basic phone interview and an analytics test.
The basic phone interview was pretty straightforward: My previous experiences, why I wanted to work at Uber, work hours and compensation. After about 20 minutes I was sent a link to take their analytics test.
The analytics test needed to be completed between 24-48 hours after it has been sent out. Once you click on the link to begin the test, you have 2 hours to complete it. It consisted of 32 questions that you would use Excel to complete: data analysis from CSV file, metrics, qualitative questions, and finally 2 essay questions. Other than the qualitative and essay questions, all other questions were multiple choice answers. Contrary to popular opinion here, I thought the analytics were not easy, given the time constraint of 2 hours.
To do well, really understand your Excel (e.g. pivot tables and search functions such as min/max, vlookup, goal seek, etc.). Also, really think about the business and the various metrics they use to track performance.