There were 3 rounds - aptitude+statistics screening, technical interview and HR interview. Aptitude was really challanging and in my opinion, only those with serious preparation can clear that. Especially, deciding which questions to attempt is critical factor. Statistics questions were relatively easy and of undergraduate level.
Technical round involves questions regarding core statistical concepts - statistical tests, survival analysis, logistic regression and odds ratio and most importantly- foundational statistical concepts like p-value and confidence interval, exploratory data analysis.
Both technical and HR round were quite well and panel was positive.