Mediator pattern in LLD - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the main purpose of the Mediator pattern?

The Mediator pattern helps reduce direct dependencies between components by centralizing communication through a mediator object. This makes the system easier to manage and change.

beginner

How does the Mediator pattern improve system design?

It promotes loose coupling by preventing components from referring to each other directly. Instead, they communicate through the mediator, which controls interactions and simplifies maintenance.

intermediate

In the Mediator pattern, what role does the mediator object play?

The mediator acts as a central hub that receives messages from components and decides how to forward or handle them, coordinating the interactions between components.

beginner

Give a real-life example that illustrates the Mediator pattern.

Think of an air traffic controller at an airport. Instead of planes communicating directly, they talk to the controller who manages takeoffs and landings, ensuring safe and organized traffic flow.

intermediate

What is a potential downside of using the Mediator pattern?

The mediator can become a complex and large object if it handles too many interactions, which might make it harder to maintain or understand.

What problem does the Mediator pattern primarily solve?

A Encrypting communication between services

B Improving database query speed

C Reducing direct dependencies between components

D Managing user authentication

The Mediator pattern reduces direct dependencies by centralizing communication through a mediator.

In the Mediator pattern, components communicate through:

A A central mediator object

B Direct references to each other

C A shared database

D Network sockets

Components send messages to a mediator, which coordinates their interactions.

Which of the following is a real-world analogy for the Mediator pattern?

A An air traffic controller managing planes

B A chef cooking a meal

C A library where books are stored

D A group chat where everyone talks directly

The air traffic controller acts as a mediator coordinating communication between planes.

What is a risk when using the Mediator pattern extensively?

A Components become tightly coupled

B Mediator becomes a bottleneck or too complex

C Communication speed increases too much

D System becomes less maintainable

The mediator can grow complex and hard to maintain if it handles too many responsibilities.

Which design principle does the Mediator pattern promote?

A Tight coupling

B Code duplication

C Direct communication

D Loose coupling

Mediator promotes loose coupling by centralizing communication.

Explain the Mediator pattern and how it helps in managing component interactions.

Think about how components avoid talking directly and use a middleman.

Describe a real-life example that illustrates the Mediator pattern and why it fits the pattern.

Consider a situation where a central figure manages communication between many parties.