Uber Sr. Software Engineer interview questions

I lost how many times I got an email from a random head hunter to participate of the hiring process. Then I accept it and was interviewed remotely, passed and then shceduled the technical interview. They shared a problem with me and I was able to solve it. It worked as expected and the interviewed congratulate me and said it was a good solution, then we discuss around the problem. Then I received a feedback saying I did not pass on the hiring process. I don't know why but that's how it is. At least I stopped receiving too much emails from hunters :)