It's just a massive interview process where they need candidates who are well-versed in mathematics what ever role you apply they will conduct 3 rounds aptitude (basic, advanced), basic mathematics (2 round) after this they will give time to prepare for mathematics exam and you need to score above 60 marks in it
Interview questions [1]
Question 1
All the maths questions you came accross from school time in the name of Mathematics in Deep learning