My experience was exactly in line with the other reviews. Upon applying. I received a 5 part case study without any actual conversation. Upon completion, I got a generic email stating they will not go ahead with the application. I'm all for an early case study, but this is one sided rigoros work for multiple hours and no feedback or conversation. My resume was an exact match for the role. The case study was very generic with hidden text to search for "over obvious" LLM use.
I see reviews on Reddit that mention this to be a scam to collect free analysis from candidates. I do not know, but I can confirm that it very much feels like it.
Also I am not convinced that an excel with no conversation is it right way to go about an interview. Employment is a two way street and requiring hours of work upfront with no investment on the company's part is not a good environment to be stepping in imo.
I'd recommend staying away.