Snap Software Engineer I interview questions

It was an initial recruiter screen after I had applied online. I was asked to set up a time to speak to one of their tech recruiters through the recruiter's appointment portal. I got a reminder 1 day before and I was called promptly.

I contacted a recruiter, and was given a coding challenge. I had a skype interview for about an hour - code and run the program. I gave the most optimal solution, but still got a reject. I haven't seen a more erratic interview process. Hardly get any replies/feedback from the recruiters.