Nielsen Data Scientist Interview Questions and Answers

I was asked to write SQL queries for 3rd highest salary of the employee, some name filtering, group by tasks.
Python code to find the index of the maximum number without using numpy.

• Q1. Explain the Project undertaken during the research and follow-up questions
  Add Answer

• Q1. Write pandas query to separate the names as first and last name from the full name. Drop the duplicate columns and also the missing values. Write output for the...read more
  View Answers (1)

Sql, python, Statistics mcq, Aptitude test. These were medium level questions.

• Q1. SQL and python, time complexity
  Add Answer
• Q2. Make 2 lists a=[1,2,3,4] b=[9,8,5,5,2,3,3,4,1,1,10,9,2,3,4,10,10,9,7,7,8] Write a program to remove duplicate of b and keep only those elements of b which are n...read more
  View Answers (2)
• Q3. SQL question Remove duplicate from a table tab1
  View Answers (2)

Given 2 case studies on data science and asked different possibilities to improve the models.

How to work with imbalance dataset.
How to remove null values, what is features engineering.
What is PCA
What is the working of XGBOOST

• Q1. What was last project, tell me in detail. There were different technical questions related to my project
  Add Answer

Test consisted 7 sections which lasted for more than a hour. There were questions related to coding , sql , analytical questions etc.

1 python coding questions and 2 Sql question

2 case study question

• Q1. This was the final round . Technical+HR .
  Add Answer