Backend

Question 1

Which three are the most common backend architectures?

Answer 1

Monolithic, micro services and serverless

Question 2

What is load balancing?

Answer 2

a technique used to distribute incoming network traffic across multiple servers

Question 3

How to ensure that no single server becomes overwhelmed with too many requests?

Answer 3

Use load balancing

Question 4

What is a load balancer?

Answer 4

A device or software that acts as an intermediary between clients and servers.

Question 5

What does a load balancer do?

Answer 5

Distribute incoming requests to multiple backend servers based on a specific algorithm.

Question 6

What is the purpose of a load balancer?

Answer 6

Improve responsiveness, availability, and reliability of the application.

Question 7

What are four common algorithms for load balancing?

Answer 7

Round Robin: distribute requests sequentially across all servers.

Least Connections: Requests are sent to the server with the fewest active connections.

IP Hash: distribute requests based on a hash of the client’s IP address, ensuring that a particular client’s requests always go to the same server.

Weighted Round Robin/Least Connections: Some servers may have more capacity and thus can handle more traffic, so weights are assigned to servers accordingly.

Question 8

What is session persistence?

Answer 8

Also known as sticky sessions, this feature ensures that a user’s session is consistently directed to the same server. This is important for applications that store session state on the server.

Question 9

Three types of load balancers?

Answer 9

Hardware, software and cloud-based.

Question 10

Whats a hardware load balancer?

Answer 10

Dedicated hardware device designed specifically for load balancing. Typically more expensive and provide high performance.

Question 11

What are software load balancers?

Answer 11

Software-based load balancers that can run on standard hardware. Examples include HAProxy, NGINX, and Apache HTTP Server.

Question 12

What are cloud-based load balancers?

Answer 12

Load balancing services provided by cloud providers, such as AWS Elastic Load Balancer (ELB), Google Cloud Load Balancing, and Azure Load Balancer.

These services offer scalability and ease of use without the need to manage hardware.

Question 13

What is a backend architecture? (And what does it define?)

Answer 13

The backbone of a web application.
Defining how servers, databases, and other resources are structured and interact with each other.

Question 14

Key features of a monolithic backend?

Answer 14

A single, unified codebase that handles all aspects of the application.

Typically includes the user interface, business logic, and data access layers in one place.

Question 15

Key feature of a micro services backend?

Answer 15

Breaks down the application into smaller, independent services, each responsible for a specific piece of functionality and can be developed, deployed, and scaled independently.

Question 16

Two key features of a ‘serverless’ backend?

Answer 16

Uses cloud services to manage the infrastructure, allowing developers to focus on writing code.

Functions as a Service (FaaS) is a common model where individual functions are deployed and executed in response to events.

Question 17

Three reasons for when to use monolithic architecture?

Answer 17

1. Simple applications with a small team.
2. Projects with tight deadlines and limited scope.
3. Early-stage startups needing rapid development and iteration.

Question 18

Name three challenges with a monolithic architecture?

Answer 18

1. Hard to scale horizontally.
2. Tight coupling makes it difficult to update or change parts of the application.
3. As the application grows, it becomes harder to maintain and deploy.

Question 19

Three key principles to follow when using monolithic backend?

Answer 19

1. Modularize the codebase to improve manageability.
2. Use clear, well-defined interfaces between different parts of the application.
3. Plan for eventual refactoring into a more scalable architecture.

Question 20

Three reasons for when to use a microservices backend?

Answer 20

1. Large, complex applications with multiple teams.
2. Applications that require high scalability and availability.
3. Projects needing rapid, frequent updates and deployments.

Question 21

Three main challenges using microservices?

Answer 21

1. Increased complexity in managing multiple services.
2. Requires robust inter-service communication and data consistency mechanisms.
3. Deployment and monitoring become more complex.

Question 22

Three key principles to follow when using microservices architecture?

Answer 22

1. Define clear service boundaries and responsibilities.
2. Implement effective communication strategies (e.g., REST, gRPC, messaging queues).
3. Use centralized logging, monitoring, and orchestration tools (e.g., Kubernetes).

Question 23

Three reasons for when to use serverless architecture?

Answer 23

1. Applications with variable or unpredictable loads.
2. Projects with tight budgets needing a pay-as-you-go model.
3. Prototyping or building MVPs (Minimum Viable Products).

Question 24

Three challenges using serverless architecture?

Answer 24

1. Cold start latency can affect performance.
2. Limited control over the underlying infrastructure.
3. Vendor lock-in with specific cloud providers.

Question 25

Three key principles when using serverless architecture?

Answer 25

1. Design for statelessness and scalability.
2. Implement effective monitoring and error handling.
3. Use managed services for databases, authentication, and other common needs.

Question 26

What three layers are often stored together in a monolith backend?

Answer 26

user interface,
business logic,
and data access layer