There were three rounds
The first round was speaking to the company about expectations. There were no technical questions, more about getting to know each other.
The second round was a code interview. I was asked to solve some questions with an AI scientist, using Python and NumPy. Then I had to provide him with a code sample of a paper in which I was the lead contributor, and walk him through the code.
The final round was a 1 hour presentation, followed by 3 1 on 1 interviews with an AI scientist, an engineering manager, and the head of AI. The presentation was about a couple of published papers which I was the main author. The interviews with AI scientist and head of AI further discussed these papers. The interview with the engineering manager was about best coding practices.
I received a rejection a week after the final interview round. All in all, the process took less than a month.