Udacity Software Engineer Backend interview questions

I applied through the website, got contacted by a recruiter who set up a phone conversation with me. She was nice and professional, asked about my experience, why I want to work at Udacity and a couple of other general questions. The first step was to either supply a code sample of a past project or do a test project. The test project was a big design problem that involves the full stack from front-end to back-end, but it was okay if I only did the relevant part. The recruiter said that candidates normally spend around 10 hours doing it. I implemented a solution, hosted it on app engine, and submitted it. I was then introduced to another recruiter and was told that I would get a reply by the end of the week. A week and half passed without getting any reply, I then sent an email to the recruiter and he replied that I will get an answer by the end of the week. Again, the week passed without getting any response. I pinged the recruiter again to ask for an update and a couple of days later I got a one-sentence reply that they will not continue the process. The communication is very slow at the company and they didn't care to contact me when they were late a couple of times, I had to always ping the recruiter to get a reply a few days after. I didn't get any feedback about my project and not even a thank-you note about the time I spent doing the project, instead I got that poor one-sentence reply.