Lambda with API Gateway pattern in AWS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the role of AWS Lambda in the Lambda with API Gateway pattern?

AWS Lambda runs your backend code without managing servers. It executes your code in response to HTTP requests sent through API Gateway.

beginner

How does API Gateway interact with Lambda functions?

API Gateway acts as a front door that receives HTTP requests and forwards them to Lambda functions for processing, then returns the Lambda response to the client.

intermediate

Why is the Lambda with API Gateway pattern considered scalable?

Because Lambda automatically scales up or down based on incoming requests, and API Gateway handles routing and throttling, the system can handle many users without manual server management.

beginner

What is a common use case for the Lambda with API Gateway pattern?

Building RESTful APIs or microservices that respond to HTTP requests without managing servers, such as user authentication or data retrieval.

intermediate

What are some best practices when designing APIs with Lambda and API Gateway?

Use proper request validation, handle errors gracefully, enable caching in API Gateway, and keep Lambda functions stateless and focused on single tasks.

What triggers a Lambda function in the Lambda with API Gateway pattern?

A A manual server restart

B A scheduled cron job

C An HTTP request received by API Gateway

D A database update

In this pattern, API Gateway receives HTTP requests and triggers the Lambda function to handle them.

Which component handles routing and throttling in the Lambda with API Gateway pattern?

A API Gateway

B Elastic Load Balancer

C Amazon S3

D AWS Lambda

API Gateway manages routing requests to Lambda and can throttle requests to protect backend resources.

Why is Lambda considered serverless in this pattern?

A Because it runs on physical servers you manage

B Because you do not manage the underlying servers

C Because it only runs on your local machine

D Because it requires manual scaling

Lambda abstracts server management, so you only focus on code without managing servers.

What is a key benefit of using API Gateway with Lambda?

A It manages user authentication by default

B It automatically creates databases

C It replaces Lambda functions

D It provides a secure and scalable HTTP interface

API Gateway provides a secure, scalable HTTP endpoint that triggers Lambda functions.

Which of the following is a best practice for Lambda functions behind API Gateway?

A Handle errors gracefully

B Keep functions stateful

C Avoid request validation

D Use Lambda for long-running tasks

Handling errors gracefully improves API reliability and user experience.

Explain the flow of a user HTTP request through the Lambda with API Gateway pattern.

Think about each step from the user to the backend and back.

Describe why the Lambda with API Gateway pattern is suitable for scalable web APIs.

Consider how the system handles many users and traffic spikes.