487 interview questions for Blockchain Expert (2026)

Easy

49 votes3429 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

19 votes3381 runs0 comment

Select only distinct values in a column using SQL

Back-end developer

sql

distinct

Vincent Cotroat Mar 27, 2023

Easy

19 votes3294 runs1 comment

Update a column in an SQL table

Back-end developer

sql

update

Vincent Cotroat Nov 7, 2023

Medium

19 votes1510 runs0 comment

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

Data Scientist

machine learning

missing data

Martinat Apr 4, 2022

Easy

17 votes3397 runs0 comment

Write a SQL query to insert data into a table

Back-end developer

sql

insert

Vincent Cotroat Mar 27, 2023

Easy

17 votes881 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 votes3361 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 votes856 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

Easy

15 votes529 runs0 comment

What does EVM stand for?

Blockchain Expert

ethereum

virtual machine

Anonymous authorat Nov 7, 2022

Medium

13 votes3327 runs4 comments

Write the SQL query to delete a column from a table

Back-end developer

sql

table

column

Vincent Cotroat Mar 27, 2023

Easy

12 votes1062 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

11 votes3307 runs0 comment

How to delete an SQL table?

Back-end developer

sql

tables

Vincent Cotroat Mar 27, 2023

Easy

11 votes3198 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

Medium

11 votes1464 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

11 votes1006 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

10 votes3284 runs0 comment

Count the number of rows in an SQL table

Back-end developer

sql

count

Vincent Cotroat Mar 27, 2023

Medium

10 votes1366 runs0 comment

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

Data Scientist

machine learning

missing data

Martinat Apr 4, 2022

Easy

10 votes557 runs0 comment

Which command in PostgreSQL is used to delete a database?

Data Scientist

abdelghaniat Apr 19, 2024

Easy

9 votes495 runs

1 comment

What is the main purpose of the LSTM (Long Short-Term Memory) model in machine learning?

Data Scientist

Artificial Intelligence

abdelghaniat Mar 26, 2024

Easy

8 votes3199 runs

2 comments

Write a SQL query to increase the salary of all employees by 10%.

Back-end developer

sql

update

salary

Vincent Cotroat Mar 28, 2023

487 interview questionsfor Blockchain Expert (2026)

Test your technical skills before an interview of Blockchain Expert with 487 corrected questions. Beginner, Intermediate or Expert level.

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

Select only distinct values in a column using SQL

Update a column in an SQL table

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

Write a SQL query to insert data into a 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?

What does EVM stand for?

Write the SQL query to delete a column from a table

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

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.

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.

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

Count the number of rows in an SQL table

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

Which command in PostgreSQL is used to delete a database?

What is the main purpose of the LSTM (Long Short-Term Memory) model in machine learning?

Write a SQL query to increase the salary of all employees by 10%.