The whole interview process was rather badly organized and unprofessional. The initial call was delayed and I as an interviewee had to contact them proactively to move forward the application several times.
1st call: general questions about background and why Uber + some brainteasers (how would you launch Uber in your city, what obstacles do you see in your city etc.)
2nd test: the same Excel test as mentioned below. Pretty easy if you have analytical background and you know excel.
What happened after that is pretty unprofessional. Even though I felt that my test result should be positive (I have done similar tests before and always passed - with MBB consulting firms for instance), I didn't get any response. I have been waiting for weeks, wrote email to the HR manager and finally 3 weeks after the test I received a general email that I won't be processed to the next round. No explanation, no apologies for the delay in response.
If you know these HR softwares at startups, you know that they just have to click on a button and they send a generic email to everyone in that bucket. I received such an email. I understand that you are busy, but you could at least write 1 line of personal explanation if I also take the time to prepare for your interviews.