Question 1

What is a REST API?

Accepted Answer

This is an MCQ screening question. The options are A) A database, B) An interface for communication between systems using HTTP, C) A frontend framework, D) A cloud storage solution. The correct answer is B. The suggested knockout rule is: 'Wrong = Hard Knockout'.

Question 2

What does SQL stand for?

Accepted Answer

This is an MCQ screening question. The options are A) Structured Query Language, B) Simple Question Logic, C) System Query Layer, D) Structured Question List. The correct answer is A. The suggested knockout rule is: 'Wrong = Basic gap'.

Question 3

What is the difference between GET and POST requests?

Accepted Answer

This is an MCQ screening question. The options are A) No difference, B) GET retrieves data; POST sends data, C) POST retrieves data; GET sends data, D) Both delete data. The correct answer is B. The suggested knockout rule is: 'Wrong = Knockout'.

Question 4

What is an ORM?

Accepted Answer

This is an MCQ screening question. The options are A) A cloud platform, B) A tool that maps database tables to code objects, C) A testing framework, D) A deployment tool. The correct answer is B. The suggested knockout rule is: 'Wrong = Red flag'.

Question 5

What is the purpose of indexing in a database?

Accepted Answer

This is an MCQ screening question. The options are A) To delete records faster, B) To speed up data retrieval queries, C) To encrypt data, D) To back up the database. The correct answer is B. The suggested knockout rule is: 'Wrong = Knockout'.

Question 6

What is JWT used for?

Accepted Answer

This is an MCQ screening question. The options are A) Styling web pages, B) Authenticating and authorizing users securely, C) Managing databases, D) Deploying applications. The correct answer is B. The suggested knockout rule is: 'Wrong = Knockout'.

Question 7

What is a microservices architecture?

Accepted Answer

This is an MCQ screening question. The options are A) A single large application, B) An application split into small independent services, C) A mobile app structure, D) A cloud database. The correct answer is B. The suggested knockout rule is: 'Wrong = Knockout for microservices roles'.

Question 8

What does 'caching' do in a backend system?

Accepted Answer

This is an MCQ screening question. The options are A) Deletes old data, B) Stores frequently accessed data for faster retrieval, C) Encrypts data, D) Backs up data. The correct answer is B. The suggested knockout rule is: 'Wrong = Red flag'.

Question 9

What is Docker used for?

Accepted Answer

This is an MCQ screening question. The options are A) Writing code, B) Packaging applications into portable containers, C) Managing databases, D) Testing APIs. The correct answer is B. The suggested knockout rule is: 'Wrong = Knockout for containerized stacks'.

Question 10

What is the role of a message queue? (e.g. Kafka, RabbitMQ)

Accepted Answer

This is an MCQ screening question. The options are A) Storing user data, B) Enabling async communication between services, C) Styling the frontend, D) Running database queries. The correct answer is B. The suggested knockout rule is: 'Wrong = Knockout for event-driven systems'.

Question 11

What is the difference between SQL and NoSQL databases?

Accepted Answer

This is an MCQ screening question. The options are A) No difference, B) SQL is structured/relational; NoSQL is flexible/non-relational, C) NoSQL is faster always, D) SQL is only for mobile apps. The correct answer is B. The suggested knockout rule is: 'Wrong = Knockout'.

Question 12

What is a foreign key in a database?

Accepted Answer

This is an MCQ screening question. The options are A) A password field, B) A field that links one table to another, C) A primary identifier, D) An encrypted column. The correct answer is B. The suggested knockout rule is: 'Wrong = Basic DB gap'.

Question 13

What does CRUD stand for?

Accepted Answer

This is an MCQ screening question. The options are A) Create, Run, Update, Delete, B) Create, Read, Update, Delete, C) Copy, Read, Undo, Deploy, D) None of the above. The correct answer is B. The suggested knockout rule is: 'Wrong = Basic gap'.

Question 14

What is rate limiting in an API?

Accepted Answer

This is an MCQ screening question. The options are A) Increasing API speed, B) Restricting number of requests a user can make in a time window, C) Deleting API endpoints, D) Caching API responses. The correct answer is B. The suggested knockout rule is: 'Wrong = Red flag for production APIs'.

Question 15

What is the purpose of environment variables?

Accepted Answer

This is an MCQ screening question. The options are A) To style the application, B) To store configuration and secrets outside the codebase, C) To manage the database, D) To run tests. The correct answer is B. The suggested knockout rule is: 'Wrong = Red flag'.

Question 16

What is a database transaction?

Accepted Answer

This is an MCQ screening question. The options are A) A single SQL query, B) A sequence of operations treated as a single unit, C) A database backup, D) A type of index. The correct answer is B. The suggested knockout rule is: 'Wrong = Red flag'.

Question 17

What does horizontal scaling mean?

Accepted Answer

This is an MCQ screening question. The options are A) Making one server more powerful, B) Adding more servers to distribute load, C) Reducing database size, D) Removing old code. The correct answer is B. The suggested knockout rule is: 'Wrong = Knockout for scale roles'.

Question 18

What is the purpose of a load balancer?

Accepted Answer

This is an MCQ screening question. The options are A) Writing code, B) Distributing traffic across multiple servers, C) Managing database queries, D) Encrypting user data. The correct answer is B. The suggested knockout rule is: 'Wrong = Red flag'.

Question 19

What is CI/CD?

Accepted Answer

This is an MCQ screening question. The options are A) A coding language, B) Automated process of integrating, testing, and deploying code, C) A type of database, D) A frontend framework. The correct answer is B. The suggested knockout rule is: 'Wrong = Red flag'.

Question 20

What is OAuth used for?

Accepted Answer

This is an MCQ screening question. The options are A) Styling web pages, B) Allowing third-party login without sharing passwords, C) Managing databases, D) Storing session data. The correct answer is B. The suggested knockout rule is: 'Wrong = Knockout for auth-heavy roles'.

MCQ Screening Questions for a Backend Developer

20 Knockout Questions for Backend Developers

Automate Your Backend Screening

#	Question	A	B	C	D	Answer	Knockout Rule
1	What is a REST API?	A database	An interface for communication between systems using HTTP	A frontend framework	A cloud storage solution	B	Wrong = Hard Knockout
2	What does SQL stand for?	Structured Query Language	Simple Question Logic	System Query Layer	Structured Question List	A	Wrong = Basic gap
3	What is the difference between GET and POST requests?	No difference	GET retrieves data; POST sends data	POST retrieves data; GET sends data	Both delete data	B	Wrong = Knockout
4	What is an ORM?	A cloud platform	A tool that maps database tables to code objects	A testing framework	A deployment tool	B	Wrong = Red flag
5	What is the purpose of indexing in a database?	To delete records faster	To speed up data retrieval queries	To encrypt data	To back up the database	B	Wrong = Knockout
6	What is JWT used for?	Styling web pages	Authenticating and authorizing users securely	Managing databases	Deploying applications	B	Wrong = Knockout
7	What is a microservices architecture?	A single large application	An application split into small independent services	A mobile app structure	A cloud database	B	Wrong = Knockout for microservices roles
8	What does 'caching' do in a backend system?	Deletes old data	Stores frequently accessed data for faster retrieval	Encrypts data	Backs up data	B	Wrong = Red flag
9	What is Docker used for?	Writing code	Packaging applications into portable containers	Managing databases	Testing APIs	B	Wrong = Knockout for containerized stacks
10	What is the role of a message queue? (e.g. Kafka, RabbitMQ)	Storing user data	Enabling async communication between services	Styling the frontend	Running database queries	B	Wrong = Knockout for event-driven systems
11	What is the difference between SQL and NoSQL databases?	No difference	SQL is structured/relational; NoSQL is flexible/non-relational	NoSQL is faster always	SQL is only for mobile apps	B	Wrong = Knockout
12	What is a foreign key in a database?	A password field	A field that links one table to another	A primary identifier	An encrypted column	B	Wrong = Basic DB gap
13	What does CRUD stand for?	Create, Run, Update, Delete	Create, Read, Update, Delete	Copy, Read, Undo, Deploy	None of the above	B	Wrong = Basic gap
14	What is rate limiting in an API?	Increasing API speed	Restricting number of requests a user can make in a time window	Deleting API endpoints	Caching API responses	B	Wrong = Red flag for production APIs
15	What is the purpose of environment variables?	To style the application	To store configuration and secrets outside the codebase	To manage the database	To run tests	B	Wrong = Red flag
16	What is a database transaction?	A single SQL query	A sequence of operations treated as a single unit	A database backup	A type of index	B	Wrong = Red flag
17	What does horizontal scaling mean?	Making one server more powerful	Adding more servers to distribute load	Reducing database size	Removing old code	B	Wrong = Knockout for scale roles
18	What is the purpose of a load balancer?	Writing code	Distributing traffic across multiple servers	Managing database queries	Encrypting user data	B	Wrong = Red flag
19	What is CI/CD?	A coding language	Automated process of integrating, testing, and deploying code	A type of database	A frontend framework	B	Wrong = Red flag
20	What is OAuth used for?	Styling web pages	Allowing third-party login without sharing passwords	Managing databases	Storing session data	B	Wrong = Knockout for auth-heavy roles