Taboola Alogrithm Engineer interview questions

Get invited for an interview from the recruiter. Get a took-home assignment with 5 really open-ended ML & algorithm problems. It took me about 4 days to finish the assignment and try to cover as many details related to the questions. HR scheduled an interview with two of their engineer two weeks after I submit the assignment. The interviewer goes through the questions and asks me to solve them again but in different ways. And there isn't too much discussion around the answers I wrote in the assignment which makes me wonder what is the purpose of doing the assignment in the first place. Receive the rejection letter one week after the interview, and got zero feedback from them. Not recommend anyone who values their own time to go through this interview process.