A Structured Approach to Analytics InterviewsANKIT JAIN

Who am I?

• Data Scientist@Uber

• Previously, led Data Science@startup in India

• Worked at Facebook, BofA

• UCB, IIT Bombay (India)

• Half Marathon Runner

• Husband

Why to enter into Data Analytics/Science?

2.5 *1018Bytes of data generated everyday (--IBM)

150,000 Shortage of Data Scientists in US alone in

2018 ( -- Mckinsey and Co.)

Analytics Interview is not Rocket Science

What are Employer’s RequirementsWhat are Employer’s Requirements?

• Technical Skills

• Knowledge of Statistics

• Structured Thinking

• Business Understanding

• Communication Skills

• Attention to details

Types of Interviews

Analytics Interview

Technical BehavioralCase

Interviews

Technical Interviews

• SQL : Joins, GroupBy , Where, Having, Window Functions, Query optimizations, NoSQL

• R/Excel : Level depends on the job

• Tableau or other BI tool: Useful if you are going for reporting/dashboardingkind of role

Guesstimates (Type 1 Case Interviews)• These are the kinds of interviews where you are required to estimate a number by putting a framework to the problem, making assumptions and coming up with a final number.

• For e.g. “ Estimate the number of balls/ liquor bottles in USA”

• Few pointers:• It is the approach that matters – not the final numbers

• Call out all the assumptions and possible blind spots

• Clearly state the framework and segmentations you make

Real Life Case StudyA case interview starts with a broad business question and narrows down in a particular direction. It generally starts with a very simple problem and then interviewers tend to increase the complexity as you solve the problems.

Few pointers:

• Case study is all about three things : Structure, Structure, Structure. Focus on putting a frame work to the problem.

• Again call out all the assumptions.

• Think out loud, interviewer is looking for your thought process

• Communicate effectively

Some more things1. Update your Linkedin profile2. Attend local meetups3. Keep yourself updated through:

1. News sites like www.datatau.com (hacker news for data science/analytics)

2. Follow data science/analytics leaders on Twitter ( for e.g DJ Patil, Andrew Ng etc. )

CASE STUDY EXAMPLE

Source : https://modeanalytics.com/

Yammer ($1.2Bn Acquisition by Microsoft)

Yammer is a social network for communicating with coworkers. Individuals share documents, updates, and ideas by posting them in groups.Think of it like Facebook for Work. Yammer has web,mobile and tablet apps.

Investigating a Drop in User Engagement

What caused this dip in engaged users?

Prior Hypothesis• Holiday

• Broken Feature/App

• Error in Data Recording Script

• One Time Marketing Event

• Etc…

User Growth on Yammer Platform

Growth Rates look normal. High on weekdays and low on weekends

Engagement of Old Users

Engagement By Device

Major Engagement Drop for Mobile Users

Zooming in on Mobile Users

Further Exploration

It seems the issue is with the mobile app related to long-time user retention. Possible issues can be:

1. Mobile app has become too heavy with new features and it crashes

2. Re-engagement Emails that were sent for retaining users are not been viewed on mobile clearly

3. A bug in recording data in mobile 4. Etc …

Thank You