DoorDash Data Scientist - Machine Learning interview questions

Lengthy take home exercise (building a model from scratch) along with a 3-4 page report. Funny that they say it should only take 5-6 hours. Keen to meet a person who can do it in that time frame. What is worse is despite spending many hours working on the problem, they do not give you the courtesy of having an interview to explain how you tackled the problem. You just get a standard one line rejection with no feedback. Other firms that do have lengthy take home assignments at least give you an opportunity to walk through your work. Don't waste your time with this company. If you do want to apply, time it well. Their competitors have a much better and systematic interviewing process, so much better to focus on those. I

The recruitment process was very cold and impersonal. A challenge was thrown at me via email without any prior calls or discussion with a recruiter. The emails gave a very "disinterested" vibe. I spent 3 days on the challenge, poured my soul, time, and sleep into it only to receive a generic email from a no-reply address saying they will not be moving forward. The email they sent was the same rejection email they would send if you were rejected after application, not fitting for someone who had gone through the pain of doing a machine learning challenge, no acknowledgments for my efforts or anything. I was confused about what position the email was even for because it was so generic. Emailed the recruiter to verify and she sent a one-liner saying it's for XXX position. No feedback, nothing. I felt so embarrassed. Even if you felt my work was bad, was it so bad that I did not deserve a decent rejection? It was a total waste of my time given that I had other interviews to prepare for which was the more painful part. I had read poor reviews on this company's recruitment process but I thought they would have taken all the feedback and improved on their process. They tell you the challenge should last for 5-6 hours but we all know that no machine learning challenge takes that amount of time especially if you are trying to give it your best shot. The whole thing made me feel so bad, a huge blow to my confidence. This would be the last time I ever interview with this company. Imagine working with people who so easily discard the hard work of others. Even bigger companies with more applicants have never treated me this way.