The interview process for a data scientist at Groupon takes 2-5 weeks in general.

• Stage 1: Phone screen with recruiter
  
• Stage 2: Phone interview with a senior data scientist
  The questions are focused on machine learning theory as well as a technical discussion of previous work experience.
  
• Stage 3: Onsite interview
  The onsite includes 5 in-person interview sessions, about 3.5 hours total. The questions are standard statistics/SQL/programming questions for the data scientist position.

• Q 1: How do you write sqrt function without using sqrt())?
• Q 2: Normal distribution, binomial distribution
• Q 3: Programing (R/Python) and probability/stats questions
• Q 4: You are on a number line and you can jump to one of the neighbor points with equal probability, with the exception of n=0 where you can't go to negative numbers but have to come back to n=1. If you start at n=44, what is the expected number of steps to reach n=4444?
• Q 5: How would you create/design/implement a certain algorithm from start to end?
• Q 6: Tell us about a recent project where you used machine learning techniques.

Groupon's mission is to become the daily habit in local commerce.

To fulfill our purpose of building strong communities through fast-growing small businesses by connecting people to a dynamic, global marketplace for local services, experiences, and goods.