Take home project: 5hours+. They are just fishing for people to improve their product. I spent a good amount of time on the model and optimized it to have a decent ROC AUC (~.9). When I discussed my project with their engineer, I was asked no questions about ML specifics, but only about how I could potentially improve the model and how to develop new features. 1-2 weeks later I was sent a generic "thanks but no thanks because we found someone better" email. After about 1.5 months, I was contacted by a recruiter for this exact same position. As others have mentioned. Its free consulting for them. A kaggle challenge with a carrot (job) on a stick. Don't waste your time.

The interview process consisted of a phone screen, a ML take home assessment, two one on one technical interviews discussing the assignment and answering technical questions, and half-day group of virtual meetings simulating an on-site interview.