1720 interview questions for Back-end developer (2026)

Medium

119 votes4680 runs

6 comments

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

Web developer

Anonymous authorat Jan 18, 2024

Easy

55 votes3796 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

Medium

50 votes4291 runs4 comments

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

Web developer

promises

async

Anonymous authorat Mar 28, 2023

Easy

44 votes2306 runs1 comment

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

Back-end developer

recursion

Anonymous authorat Mar 28, 2023

Easy

40 votes3386 runs

13 comments

Write a Java program that prints 'welovedev'.

Full stack developer

strings

variables

Pierreat Sep 19, 2022

Easy

39 votes2364 runs1 comment

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

Back-end developer

functions

errors

Anonymous authorat Mar 24, 2023

Easy

32 votes4378 runs

2 comments

Fix the following Javascript loop:

Web developer

loops

conditions

Anonymous authorat Apr 27, 2023

Hard

27 votes2674 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

Easy

26 votes969 runs1 comment

What is the purpose of the Laravel Sanctum tool?

Web developer

laravel

authentication

Damienat Sep 6, 2023

Easy

21 votes3758 runs0 comment

Write a SQL query to insert data into a table

Back-end developer

sql

insert

Anonymous authorat Mar 27, 2023

Easy

21 votes3744 runs0 comment

Select only distinct values in a column using SQL

Back-end developer

sql

distinct

Anonymous authorat Mar 27, 2023

Easy

19 votes3647 runs1 comment

Update a column in an SQL table

Back-end developer

sql

update

Anonymous authorat Nov 7, 2023

Medium

18 votes3070 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

17 votes3719 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

Hard

17 votes3680 runs

1 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

Easy

17 votes3277 runs

2 comments

How should a package be named in Java?

Full stack developer

packages

java

Pierreat Sep 19, 2022

Medium

17 votes3028 runs0 comment

Explain the prototype scope in Spring

Back-end developer

spring

bean

Anonymous authorat Dec 21, 2021

Easy

16 votes4773 runs

5 comments

The certificate variable is not attainable outside the if loop

Web developer

variables

scope

Anonymous authorat Apr 6, 2022

Easy

16 votes3751 runs1 comment

What is the minimum PHP version for Symfony 5?

Back-end developer

php

symfony

Smaïne Millaniat Dec 3, 2021

Easy

16 votes1012 runs0 comment

What is the best practice to apply in your code to improve the performance of your application?

Back-end developer

performance

gzip

Anonymous authorat Nov 15, 2023

1720 interview questionsfor Back-end developer (2026)

Test your technical skills before an interview of Back-end developer with 1720 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.

Write a Java program that prints 'welovedev'.

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

Fix the following Javascript loop:

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

What is the purpose of the Laravel Sanctum tool?

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

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

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

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; } ```

How should a package be named in Java?

Explain the prototype scope in Spring

The certificate variable is not attainable outside the if loop

What is the minimum PHP version for Symfony 5?

What is the best practice to apply in your code to improve the performance of your application?