Separation of concerns in LLD - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Identify the main benefit of separation of concerns in system design

Which of the following best describes the primary benefit of applying separation of concerns in a software system?

A It eliminates the need for testing by making the system simpler.

B It reduces the number of lines of code by combining all functionalities into one module.

C It increases system complexity by mixing user interface and business logic together.

D It improves system maintainability by isolating different responsibilities into distinct modules.

💡 Hint

Think about how dividing tasks helps when you need to change or fix parts of a system.

Separation of concerns divides a system into distinct sections, each handling a specific responsibility. This makes the system easier to maintain and update.

❓ Architecture

intermediate

Choose the correct layering to separate concerns in a web application

In a typical web application, which layering correctly separates concerns according to best practices?

A Presentation layer, Business logic layer, Data access layer

B Data access layer, Presentation layer, Business logic layer

C Business logic layer, Data access layer, Presentation layer

D Presentation layer, Data access layer, Business logic layer

💡 Hint

Consider the flow of data from user input to storage and back.

The presentation layer handles user interface, the business logic layer processes data and rules, and the data access layer manages storage. This order cleanly separates concerns.

❓ scaling

advanced

Scaling a system with separation of concerns

You have a system separated into three services: user interface, business logic, and database access. Which scaling approach best follows separation of concerns principles?

A Scale only the database access service since it handles all data.

B Scale each service independently based on its load and resource needs.

C Scale the user interface and business logic together as a single unit.

D Scale the entire system by duplicating all services equally regardless of load.

💡 Hint

Think about which parts of the system might need more resources at different times.

Separating concerns allows independent scaling of each service based on its specific demands, improving efficiency and cost-effectiveness.

❓ tradeoff

advanced

Tradeoff of strict separation of concerns in system design

What is a common tradeoff when applying very strict separation of concerns in a system?

A Increased complexity in communication between modules can lead to performance overhead.

B Decreased ability to test modules independently.

C Reduced code readability because all logic is combined in one place.

D Elimination of the need for documentation.

💡 Hint

Consider what happens when many small parts need to talk to each other.

Strict separation can cause more communication between modules, which may slow down the system due to overhead.

❓ component

expert

Identify the component violating separation of concerns

Given a system with components: Authentication, User Profile, Payment Processing, and Notification. Which component violates separation of concerns if it handles both payment logic and sending emails?

A Notification

B Authentication

C Payment Processing

D User Profile

💡 Hint

Think about what each component's main responsibility should be.

Payment Processing should only handle payment logic. Sending emails belongs to Notification. Combining both violates separation of concerns.