489 interview questions for Blockchain Expert (2026)

Easy

55 votes3780 runs0 comment

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

Back-end developer

sql

select

where

Anonymous authorat Mar 30, 2023

Easy

21 votes3742 runs0 comment

Write a SQL query to insert data into a table

Back-end developer

sql

insert

Anonymous authorat Mar 27, 2023

Easy

21 votes3728 runs0 comment

Select only distinct values in a column using SQL

Back-end developer

sql

distinct

Anonymous authorat Mar 27, 2023

Medium

21 votes1626 runs0 comment

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

Data Scientist

machine learning

missing data

Martinat Apr 4, 2022

Easy

19 votes3633 runs1 comment

Update a column in an SQL table

Back-end developer

sql

update

Anonymous authorat Nov 7, 2023

Easy

18 votes940 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

17 votes3704 runs0 comment

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

Back-end developer

sql

order by

Anonymous authorat Mar 27, 2023

Easy

16 votes915 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

16 votes538 runs0 comment

What does EVM stand for?

Blockchain Expert

ethereum

virtual machine

Anonymous authorat Nov 7, 2022

Medium

14 votes3672 runs4 comments

Write the SQL query to delete a column from a table

Back-end developer

sql

table

column

Anonymous authorat Mar 27, 2023

Easy

13 votes1057 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

12 votes1579 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

Medium

12 votes1471 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 votes1125 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 votes3640 runs0 comment

How to delete an SQL table?

Back-end developer

sql

tables

Anonymous authorat Mar 27, 2023

Easy

11 votes3528 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

Anonymous authorat Mar 28, 2023

Easy

11 votes595 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

10 votes3620 runs0 comment

Count the number of rows in an SQL table

Back-end developer

sql

count

Anonymous authorat Mar 27, 2023

Easy

10 votes3529 runs

2 comments

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

Back-end developer

sql

update

salary

Anonymous authorat Mar 28, 2023

Easy

10 votes674 runs0 comment

Which command in PostgreSQL is used to delete a database?

Data Scientist

abdelghaniat Apr 19, 2024

489 interview questionsfor Blockchain Expert (2026)

Test your technical skills before an interview of Blockchain Expert with 489 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 SQL query to insert data into a table

Select only distinct values in a column using SQL

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

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?

What does EVM stand for?

Write the SQL query to delete a column from a table

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

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

Count the number of rows in an SQL table

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

Which command in PostgreSQL is used to delete a database?