As someone who has had bad data science interviews before getting my current data science job, the process is highly variable. I've had interviews where the interviewer is looking for a specific right answer, with the answer being a binary you-know-it-or-you-don't thing that can't be talked through or worked out in a dialogue with the interviewer.

An example was a whiteboard problem requiring the BETWEEN syntax for SQL window functions, which is very uncommon. After I asked for a hint, the interviewer replied "You don't know the BETWEEN syntax for window functions? Everyone knows that."