Booking.com Developer interview questions

After I applied, I got an automatically generated email with a link to a hackerrank challenge. It was pretty basic Java/Spring Boot implementation of a REST API. A day after, I got an automatically generated email that we wouldn't proceed further. At no point did someone bother to reach out and add a human touch to the communication. It would have been minimum courtesy to offer some feedback on the challenge. The treatment is a major red flag and it seems I dodged a bullet anyway.