Back-End Development Basics of Back End Development 4

Question 1

What is the purpose of database indexing?

Accepted Answer

To speed up data retrieval by creating a fast-lookup data structure

Answer

An index creates an auxiliary data structure (often a B-tree) that allows the database engine to find matching rows without scanning the entire table.

Question 2

Which design pattern separates an application into three concerns: data, business logic, and presentation?

Accepted Answer

MVC (Model-View-Controller)

Answer

MVC divides responsibility into the Model (data/business logic), View (presentation), and Controller (input handling), making code easier to maintain and test.

Question 3

What does the term 'N+1 query problem' refer to in back-end development?

Accepted Answer

Running one query to fetch a list and then one additional query per list item

Answer

The N+1 problem occurs when code fetches a list of N items and then lazily runs a separate query for each, resulting in N+1 total queries that could be replaced by a single JOIN or eager load.

Question 4

Which of the following is a key benefit of using a message queue (e.g., RabbitMQ, SQS) in a back-end system?

Accepted Answer

It decouples producers and consumers, allowing asynchronous processing

Answer

Message queues allow services to communicate without being tightly coupled, letting producers and consumers operate at different speeds and fail independently.

Question 5

What is the purpose of a reverse proxy like Nginx in a back-end setup?

Accepted Answer

Sitting in front of application servers to handle routing, SSL, and load balancing

Answer

A reverse proxy receives client requests and forwards them to one or more backend servers, also handling SSL termination, caching, and load distribution.

Back-End Development Practice Test

Back-End Development Practice Test

Back-End Development Basics of Back End Development 4