Yahoo Mail Sr DS interview process

I've been contacted by a technical recruiter at Yahoo Mail for a Sr Data Scientist for Communications (Yahoo Mail) position in the Yahoo Research, Analytics, and Data organization, which is the driving force behind experimental analysis, data science and business intelligence for Yahoo Mail. Would appreciate any advice on: 1) How to prepare for a 30min call with the technical recruiter who contacted me? 2) What are the interviews/technical assessments that i could start preparing for the future rounds if I qualify? #tech #datascience #yahoo