535 interview questions for Data Scientist (2026)

Easy

52 votes3611 runs0 comment

Write a SQL query to retrieve the list of employees with a salary greater than 5100.

Back-end developer

sql

select

where

Vincent Cotroat Mar 30, 2023

Easy

42 votes2192 runs1 comment

Write a Python function that returns the factorial of a number.

Back-end developer

recursion

Vincent Cotroat Mar 28, 2023

Hard

26 votes2563 runs

1 comment

Write a Python function that prints the elements of a list.

Back-end developer

list

for loop

Anonymous authorat Mar 28, 2022

Medium

21 votes1580 runs0 comment

How to handle missing data in a given training data set ?

Data Scientist

machine learning

missing data

Martinat Apr 4, 2022

Easy

20 votes3575 runs0 comment

Write a SQL query to insert data into a table

Back-end developer

sql

insert

Vincent Cotroat Mar 27, 2023

Easy

20 votes3560 runs0 comment

Select only distinct values in a column using SQL

Back-end developer

sql

distinct

Vincent Cotroat Mar 27, 2023

Easy

19 votes3469 runs1 comment

Update a column in an SQL table

Back-end developer

sql

update

Vincent Cotroat Nov 7, 2023

Easy

18 votes918 runs0 comment

What is the missing word in the following sentence: Overfitting is the production of a model that corresponds too closely to the training data set and may therefore fail to fit other data sets and so fail to perform any reliable forecast.

Data Scientist

overfitting

Martinat Mar 14, 2022

Easy

16 votes3536 runs0 comment

Which SQL keyword is used to sort the result of a SELECT statement?

Back-end developer

sql

order by

Vincent Cotroat Mar 27, 2023

Easy

16 votes894 runs0 comment

What is the relation between Artificial intelligence (AI), machine learning and deep learning?

Data Scientist

machine learning

deep learning

Martinat Sep 19, 2022

Hard

14 votes3504 runs4 comments

Write the SQL query to delete a column from a table

Back-end developer

sql

table

column

Vincent Cotroat Mar 27, 2023

Medium

12 votes2328 runs0 comment

Use the zip() function to iterate over two lists in parallel.

Back-end developer

list

zip

Anonymous authorat Mar 28, 2022

Medium

12 votes1431 runs0 comment

How to handle missing data in a given training data set ?

Data Scientist

machine learning

missing data

Martinat Apr 4, 2022

Easy

12 votes1104 runs0 comment

What is the value of the decision threshold used with logistic regression in Scikit-learn?

Data Scientist

scikit-learn

threshold

logistic regression

Anonymous authorat Apr 6, 2022

Easy

12 votes1038 runs0 comment

How is the error calculated during back propagation in a neural network?

Data Scientist

neural network

back propagation

Anonymous authorat Apr 6, 2022

Easy

11 votes3474 runs0 comment

How to delete an SQL table?

Back-end developer

sql

tables

Vincent Cotroat Mar 27, 2023

Easy

11 votes3367 runs0 comment

Write a SQL query to retrieve the products with a price less than 1000 and sort the results in descending order of price.

Back-end developer

sql

order by

descending

Vincent Cotroat Mar 28, 2023

Easy

11 votes2295 runs0 comment

What type is `function_a` in the following code ?

Back-end developer

functions

decorators

Anonymous authorat Mar 28, 2022

Medium

11 votes1533 runs0 comment

The validation set is used to provide frequent and unbiased evaluations of the model’s fit on the training set while tuning its hyperparameters/parameters: in other words,the model is found and then tested on the validation set before to be improved once again.

Data Scientist

hyperparameters

model

Martinat Mar 15, 2022

Easy

10 votes3455 runs0 comment

Count the number of rows in an SQL table

Back-end developer

sql

count

Vincent Cotroat Mar 27, 2023

535 interview questionsfor Data Scientist (2026)

Test your technical skills before an interview of Data Scientist with 535 corrected questions. Beginner, Intermediate or Expert level.

Write a SQL query to retrieve the list of employees with a salary greater than 5100.

Write a Python function that returns the factorial of a number.

Write a Python function that prints the elements of a list.

How to handle missing data in a given training data set ?

Write a SQL query to insert data into a table

Select only distinct values in a column using SQL

Update a column in an SQL table

What is the missing word in the following sentence: Overfitting is the production of a model that corresponds too closely to the training data set and may therefore fail to fit other data sets and so fail to perform any reliable forecast.

Which SQL keyword is used to sort the result of a SELECT statement?

What is the relation between Artificial intelligence (AI), machine learning and deep learning?

Write the SQL query to delete a column from a table

Use the zip() function to iterate over two lists in parallel.

How to handle missing data in a given training data set ?

What is the value of the decision threshold used with logistic regression in Scikit-learn?

How is the error calculated during back propagation in a neural network?

How to delete an SQL table?

Write a SQL query to retrieve the products with a price less than 1000 and sort the results in descending order of price.

What type is `function_a` in the following code ?

The validation set is used to provide frequent and unbiased evaluations of the model’s fit on the training set while tuning its hyperparameters/parameters: in other words,the model is found and then tested on the validation set before to be improved once again.

Count the number of rows in an SQL table