1629 interview questions for Back-end developer (2025)

Medium

85 votes3405 runs5 comments

Understanding the differences between `map()` and `forEach()` methods in JavaScript

Web developer

Vincent Cotroat Jan 18, 2024

Easy

38 votes2680 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

Medium

37 votes3118 runs4 comments

Write a JavaScript function that fetches data from an API and logs it to the console.

Web developer

promises

async

Vincent Cotroat Mar 28, 2023

Easy

31 votes1600 runs1 comment

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

Back-end developer

recursion

Vincent Cotroat Mar 28, 2023

Easy

27 votes1689 runs1 comment

Explain the difference between the `include` and `require` functions in PHP.

Back-end developer

functions

errors

Vincent Cotroat Mar 24, 2023

Easy

25 votes2549 runs

9 comments

Write a Java program that prints 'welovedev'.

Full stack developer

strings

variables

Pierreat Sep 19, 2022

Easy

23 votes3250 runs

2 comments

Fix the following Javascript loop:

Web developer

loops

conditions

Camilleat Apr 27, 2023

Expert

19 votes1973 runs0 comment

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

Back-end developer

list

for loop

Théoat Mar 28, 2022

Easy

18 votes2639 runs0 comment

Select only distinct values in a column using SQL

Back-end developer

sql

distinct

Vincent Cotroat Mar 27, 2023

Easy

18 votes524 runs1 comment

What is the purpose of the Laravel Sanctum tool?

Web developer

laravel

authentication

Damienat Sep 6, 2023

Hard

16 votes3137 runs0 comment

How many times is the condition `(a++ < 15)` evaluated in the following code? ```java int a = 3; while (a++ < 15) { if ((a++ % 5) == 0) break; } ```

Back-end developer

loops

control flow

Thomas De verdièreat Dec 16, 2021

Medium

16 votes2551 runs0 comment

Explain the prototype scope in Spring

Back-end developer

spring

bean

Anonymous authorat Dec 21, 2021

Easy

15 votes2655 runs0 comment

Write a SQL query to insert data into a table

Back-end developer

sql

insert

Vincent Cotroat Mar 27, 2023

Easy

15 votes2569 runs1 comment

Update a column in an SQL table

Back-end developer

sql

update

Vincent Cotroat Nov 7, 2023

Easy

14 votes2620 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

Medium

14 votes2616 runs2 comments

A bean with a `session` scope is injected into a bean with a` singleton` scope. What happens when the application starts?

Back-end developer

spring

scope

Anonymous authorat Dec 21, 2021

Easy

13 votes3595 runs1 comment

What is the minimum PHP version for Symfony 5?

Back-end developer

php

symfony

Smaïne Millaniat Dec 3, 2021

Hard

12 votes3086 runs0 comment

A monitor in Java

Back-end developer

java

thread

Thomas De verdièreat Jan 4, 2022

Hard

11 votes3125 runs1 comment

Serialization can be customized with the Externalizable interface

Back-end developer

serialization

interface

Thomas De verdièreat Jan 4, 2022

Easy

11 votes3065 runs0 comment

What does the final keyword mean in front of a method in Java?

Back-end developer

java

methods

Thomas De verdièreat Jan 4, 2022

1629 interview questionsfor Back-end developer (2025)

Test your technical skills before an interview of Back-end developer with 1629 corrected questions. Beginner, Intermediate or Expert level.

Understanding the differences between `map()` and `forEach()` methods in JavaScript

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

Write a JavaScript function that fetches data from an API and logs it to the console.

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

Explain the difference between the `include` and `require` functions in PHP.

Write a Java program that prints 'welovedev'.

Fix the following Javascript loop:

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

Select only distinct values in a column using SQL

What is the purpose of the Laravel Sanctum tool?

How many times is the condition `(a++ < 15)` evaluated in the following code? ```java int a = 3; while (a++ < 15) { if ((a++ % 5) == 0) break; } ```

Explain the prototype scope in Spring

Write a SQL query to insert data into a table

Update a column in an SQL table

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

A bean with a `session` scope is injected into a bean with a` singleton` scope. What happens when the application starts?

What is the minimum PHP version for Symfony 5?

A monitor in Java

Serialization can be customized with the Externalizable interface

What does the final keyword mean in front of a method in Java?