Essential Architectural Building Blocks and Patterns

Question 1

What are the core principles of API Design?

Answer 1

RESTful principles, versioning, authentication/authorization

REST (Representational State Transfer) principles include statelessness, cacheability, and a uniform interface.

Question 2

What is the difference between SQL and NoSQL databases?

Answer 2

SQL is structured and relational, while NoSQL is non-relational and can be document-based, key-value, column-family, or graph

SQL databases use structured query language, while NoSQL databases are more flexible in data storage.

Question 3

When should you use NoSQL databases?

Answer 3

When handling large volumes of unstructured data, requiring high scalability and flexibility

Common use cases include big data applications and real-time web apps.

Question 4

What are common types of NoSQL databases?

Answer 4

• Key-value
• Document
• Column-family
• Graph

Each type has specific use cases, such as key-value stores for caching and graph databases for social networks.

Question 5

Why is indexing important in databases?

Answer 5

It improves query performance by allowing faster data retrieval

Indexes can significantly reduce the amount of data scanned during queries.

Question 6

What are the different levels of caching placement?

Answer 6

• Client
• CDN
• Application-level
• Database-level

Each level has its own benefits and trade-offs in terms of speed and consistency.

Question 7

What are common caching strategies?

Answer 7

• Write-through
• Write-back
• LRU (Least Recently Used)
• LFU (Least Frequently Used)

These strategies help manage how data is stored and retrieved in cache.

Question 8

What is a common challenge in caching?

Answer 8

Invalidation

Keeping cached data consistent with the underlying data can be complex.

Question 9

What is the purpose of message queues?

Answer 9

Asynchronous communication, decoupling, buffering, fan-out

They help manage communication between different services or components in a system.

Question 10

Name two examples of message queues.

Answer 10

• Kafka
• RabbitMQ

Both are popular tools for handling message brokering and event streaming.

Question 11

What are the pros of microservices?

Answer 11

Scalability, flexibility, and independent deployment

Microservices allow teams to work on different components without affecting the whole system.

Question 12

What are the cons of microservices?

Answer 12

Increased complexity, potential for inter-service communication issues

Managing many microservices can lead to challenges in coordination and consistency.

Question 13

What is the CQRS design pattern?

Answer 13

Separates reads and writes to optimize performance

CQRS stands for Command Query Responsibility Segregation.

Question 14

What is the Bulkhead design pattern?

Answer 14

Isolates failures to prevent system-wide outages

This pattern helps maintain service availability by containing faults.

Question 15

What does the Circuit Breaker pattern do?

Answer 15

Prevents cascading failures in a system

It allows a system to gracefully handle failures and avoid overwhelming dependent services.

Question 16

What is the Publisher/Subscriber design pattern?

Answer 16

Decouples components and allows asynchronous communication

This pattern helps in building event-driven architectures.

Question 17

What is the purpose of the Retry Pattern?

Answer 17

Handles transient failures by retrying requests

It is commonly used in distributed systems to improve reliability.