Data Interview Questions

business sense: There are two types of cars A and B. The number of people in US who use A and B are the same. They drive the same distances each month. Now there are two new technologies, X and Y (of equal cost). If apply X, mpg of A would increase from 50 mpg to 75 mpg; If apply Y, mpg of B would increase from 10 mpg to 11 mpg. The goal is to decrease the dependence on foreign oil, or to decrease the consumption of gasoline. Question: which technology would you apply? Follow up question: after applying the technology of your choice, assume there's money available for research on new technology, which car would you choose to conduct research on?

Data Scientist

Interviewed at Meta

3.6★

Jan 7, 2015

business sense: There are two types of cars A and B. The number of people in US who use A and B are the same. They drive the same distances each month. Now there are two new technologies, X and Y (of equal cost). If apply X, mpg of A would increase from 50 mpg to 75 mpg; If apply Y, mpg of B would increase from 10 mpg to 11 mpg. The goal is to decrease the dependence on foreign oil, or to decrease the consumption of gasoline. Question: which technology would you apply? Follow up question: after applying the technology of your choice, assume there's money available for research on new technology, which car would you choose to conduct research on?

In python code, given a json object with nested objects, write a function that flattens all the objects to a single key value dictionary. Do not use the lib that actually performs this function. { a:{b:c,d:e} } becomes {a_b:c, a_d:e} ( not, a:"b:c,d:e" }

Data Engineer

Interviewed at Amazon

3.5★

Apr 29, 2020

In python code, given a json object with nested objects, write a function that flattens all the objects to a single key value dictionary. Do not use the lib that actually performs this function. { a:{b:c,d:e} } becomes {a_b:c, a_d:e} ( not, a:"b:c,d:e" }

if there are 5 people in a room and each chooses a number from 1 to 10 at random what is the probability that two or more people have the same number

Data Analyst

Interviewed at BAE Systems

3.9★

Jan 1, 2010

if there are 5 people in a room and each chooses a number from 1 to 10 at random what is the probability that two or more people have the same number

They just asked for past experiences.

Data Entry

Interviewed at H2 Wellness

2.6★

Jan 17, 2021

They just asked for past experiences.

Given a random generator that produces a number 1 to 5 uniformly, write a function that produces a number from 1 to 7 uniformly or something like that.

Data Scientist

Interviewed at LinkedIn

3.8★

Mar 19, 2018

Given a random generator that produces a number 1 to 5 uniformly, write a function that produces a number from 1 to 7 uniformly or something like that.

16p + 1 = x^3, and p is a prime number. What is x?

Data Scientist - Low Latency

Interviewed at Citadel

4★

Nov 4, 2016

16p + 1 = x^3, and p is a prime number. What is x?

Given three tables, user_dimension (user_id and account_id), account_dimension (account_id and paying_customer), and download_facts (date, user_id, and downloads), find the average number of downloads for free vs paying customers broken out by day.

Data Analyst

Interviewed at Uber

3.7★

Jun 2, 2017

Given three tables, user_dimension (user_id and account_id), account_dimension (account_id and paying_customer), and download_facts (date, user_id, and downloads), find the average number of downloads for free vs paying customers broken out by day.

Python Questions - 1) Print Max element of a given list 2) Print median of a given list 3) Print the first nonrecurring element in a list 4) Print the most recurring element in a list 5) Greatest common Factor

Data Engineer

Interviewed at Meta

3.6★

May 24, 2016

Python Questions - 1) Print Max element of a given list 2) Print median of a given list 3) Print the first nonrecurring element in a list 4) Print the most recurring element in a list 5) Greatest common Factor

SQL Select the value of a column based on the max of a different column from each grouping of yet a third column. Column A, Column B, Column C. For each group based on Column A, give value of Column B, where Column C is max for that group.

Data Engineer

Interviewed at Amazon

3.5★

Apr 29, 2020

SQL Select the value of a column based on the max of a different column from each grouping of yet a third column. Column A, Column B, Column C. For each group based on Column A, give value of Column B, where Column C is max for that group.

SQL part1 Question # 1 : you have the following table - User_id , action (post, edit, cancel) , date == > what is the post rate Question # 2 : you have also the following table (active users) - User_id , country , active , date == > What is the average post rate for yesterday for all active users by country

Data Scientist

Interviewed at Meta

3.6★

Aug 7, 2019

SQL part1 Question # 1 : you have the following table - User_id , action (post, edit, cancel) , date == > what is the post rate Question # 2 : you have also the following table (active users) - User_id , country , active , date == > What is the average post rate for yesterday for all active users by country

Data Interview Questions

132,688 data interview questions shared by candidates

See Interview Questions for Similar Jobs