I asked a friend to help me refer for a software engineer position. HR set up a phone screen and gave me a code challenge. That week, I was really busy interviewing and gave them one of my existing projects (they allowed me to do that). After that, they thought it was good and moved forward to a technical phone screen. This week, the recruiter sent me an email stating that after reviewing my code again, they wanted to cancel my phone screen. This is the first time I've encountered this situation. It totally doesn't make sense; it was just a phone screen, come on! My project is not bad at all. They wasted a few days of my time preparing for them. In their email, they said they didn't provide any feedback and asked me to reapply after one year. Almost the worst interview experience I've had before. I am an Uber user, and after this, I don't like it anymore.

Code challenges are on Uber's GitHub page.