There are 3 interviews: one online coding challenge, one machine learning basic phone interview, and one onsite interview about both software engineer and machine learning stuffs.
I first started with the online coding challenge. There were 2 parts: multiple choice questions about basic classical machine learning and one coding problem. The multiple questions weren't very hard. The coding problem needs a bit of effort, but it was a standard challenge anyone can find on leetcode/hackkerrank.
The next interview was a 30-40min phone interview about deep learning. Basically, they will test your knowledge about neural network from activation layers. batchnorm, initialization, etc..
Lastly, I was invited to have a 4 hrs onsite interview with the ML members of the company and CTO. There were 5 small interviews sections: classical ML, math & probability, algorithm, deep learning, and behaviors question. It was definitely a long and exhausted interview, but overall, I had positive experience.