Petal Software Engineer interview questions

I applied online and received an online invite to schedule a call with a recruiter. She asked me about myself and went over the resume. In a week I received an invitation for an online Zoom interview. I was asked one question. It was not super hard, however, I did not find the most optimal solution for it. I got an email from the recruiter in a week asking if I am still interested in a position. Later, I got another email with an update that they decided to close this position.

HR phone call. Basic resume screen and explained projects. Detailed behavioral questions. Shortly received rejection email. How do you reject candidates after HR phone call? Got the impression that company is a mess run by people who don't know what they're doing.