Typical data science interview process: Video screening --> Phone technical interview --> Onsite interview.
The onsite interview lasts around 5 hours. You will start with a writing test, about 6 programming questions in 30 minutes, you need to write code by hand(Python/R, SQL), according to them, no one can finished those questions in 30 minutes, just try your best.
And then you will have to speak with 3 people(Technical + behavioral) and finally a case presentation including Q&A session.