Nielsen Intern interview questions

I applied online and was first interviewed with a Recruiter. Subsequently, I was emailed a link for a technical assessment for which 115 minutes were allocated. A day or two later I was invited to interview with several managers and a few days later was invited for a final panel interview. Everything progressed quickly and everyone was professional. The internship projects seemed super interesting and aligned with my background. That said, after the panel interview, I never heard back from anyone. I cannot understand how a company believes its OK to not get back to a candidate after completing an assessment of close to 2 hours and multiple interviews. An automated rejection letter doesn't take much effort and leaves a better impression than being ghosted.

Interview process involved out of the box questions. The interviewer also asked questions about my experiences thus far academically. I think the toughest portion was answering the out of the box questions and showing how I calculated my answers on paper.