The process:

• is extremely long (~5 months)
• is very relevant to the role: they evaluate skills that are directly related to the job (in my ~70 companies' interview experience, this is not the case for most of them)
• gives many useful insights on the role itself and what it is like to work in the company.

The interviewers are very kind and excited to tell you about what they do.

The questions are rather easy; you basically need a very good knowledge of some 101 college courses (algorithms, software development, machine learning, statistics, probabilities), but it doesn't dive too deep into the details.

It doesn't mean that it is easy to answer! Stress overwhelmed me several times, and I lost my abilities, but the interviewers were understanding and not stressful.

Mostly, they want to know if you REALLY REALLY want to work for them, which has been the leitmotif over the 10+ interviews (meeting ~16 different people in total).

Why do you want to work here?

Describe a method of clustering.

Describe a reinforcement learning algorithm.

What is polymorphism?

Write an algorithm to copy a linked list.

What do you expect from your manager?

Why shouldn't we hire you?

If you had infinite time and money, what would you do?

What is something you like doing in your free time?

Why is the speedup associated with parallel computing with 10 GPUs not 10x?

Are you sure you want to work here?

Why don't you do a PhD?

What do you like about this particular role?