Notification system design in HLD - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the main purpose of a notification system in software architecture?

To deliver timely messages or alerts to users or systems, ensuring they receive important information or updates.

beginner

Name two common types of notifications in system design.

Push notifications (sent to devices) and email notifications (sent via email servers).

intermediate

Why is scalability important in a notification system?

Because the system must handle increasing numbers of users and messages without delays or failures, especially during peak times.

intermediate

What role does a message queue play in a notification system?

It temporarily stores notifications to be processed asynchronously, helping to balance load and improve reliability.

advanced

How can a notification system ensure message delivery reliability?

By implementing retries, acknowledgments, and durable storage to avoid message loss and confirm delivery.

Which component is typically responsible for sending notifications to users?

A Cache

B Database

C Load balancer

D Notification sender service

The notification sender service handles the actual delivery of messages to users.

What is the benefit of using a message queue in a notification system?

A To store user profiles

B To increase database size

C To process notifications asynchronously

D To reduce network bandwidth

Message queues allow notifications to be processed asynchronously, improving system scalability and reliability.

Which of the following is NOT a common notification channel?

A FTP

B Email

C SMS

D Push notifications

FTP is a file transfer protocol and not used for sending notifications.

How can a notification system handle peak loads effectively?

A By scaling horizontally and using queues

B By ignoring some notifications

C By storing notifications only in memory

D By sending notifications synchronously

Scaling horizontally and using message queues helps handle peak loads without dropping messages.

What is a common method to confirm that a notification was delivered?

A Load balancing

B User acknowledgment

C Database backup

D Caching

User acknowledgment or delivery receipts confirm that notifications reached the user.

Explain the key components of a scalable notification system and how they interact.

Think about how messages flow from creation to delivery.

Describe strategies to ensure reliability and fault tolerance in a notification system.

Consider what happens if a message fails to deliver.