Cruise Software Engineer Algorithm interview questions

I applied on 9/3 and got an online challenge two days later. Although no specified time window for the challenges, I still asked if the response can be accepted after a week due to other ongoing process . No feedback. A week later I finished the challenge and sent it back. Never heard back ever until I send a reminder email on 9/25. The HR said he will ping the reviewer to see the progress. Then after another 9 days without response, I received a normal rejection letter mentioning about how extremely talented applicants they are busy reviewing. The hiring process I heard in Cruise Automation are very smooth, but in my case it's purely unprofessional.