In the AWS API Gateway interview questions and answers blog, we share all the latest updates, news, and insights related to AWS API gateway technology.

It refers to Amazon Web Services tools that enable developers to build, deploy and manage APIs quickly.

APIs available through AWS allow access to its wealth of resources and functionality, providing users with the tools they need to build scalable applications efficiently and flexibly.

1. What is the default event for a Lambda function?

A Lambda function’s default event occurs when setting up a REST endpoint and invoking its Lambda function via API Gateway.

2. What is the API Gateway section?

API Gateway’s section offers valuable resources for learning its capabilities.

3. How do you select the transaction processor in API Gateway?

We will choose our transaction processor and set its default timeout value in Lambda functions.

4. How do you expand the GET function in API Gateway?

To expand API Gateway’s GET function, click on its URL endpoint and provide appropriate query string parameters.

5. What is AWS API Gateway?

Amazon Web Services’ AWS API Gateway service enables developers to quickly create, monitor, maintain, and secure various APIs such as rest APIs, HTTP, or web sockets of any size or scale.

6. What are WebSocket APIs?

WebSocket APIs are collections of WebSocket Roots and Root Keys tied into HTTP Endpoints, Lambda Functions or AWS Services, which can be deployed gradually over multiple stages.

7. What is APK development?

APK development refers to taking an exact snapshot of your APK Gateway at one particular moment and making that snapshot available for customers’ use, typically associated with one or more APK stages.

8. What is the APK stage?

APK stages are logical references representing each state in your APK’s lifecycle and are identified with its ID and stage name.

9. What is an APK key?

APK keys are alphanumeric strings APK Gateway uses to identify app developers using your REST API or web socket service.

10. What is a mapping template?

A mapping template is a script written in velocity template language that changes request bodies between front-end data formats to back-end formats or vice versa or response bodies from back to front-end formats.

11. What is the motivation for AWS Lambda?

A reason is that for any AWS service or resource used to invoke an AWS Lambda function, users can link roles directly with a stimulus by selecting the “add trigger” option in the Lambda console.

12. What API Gateway permission is given to invoke the Lambda function?

Permission to invoke Lambda functions has been granted through API Gateway.

13. How is a new Lambda function created and a parameter added?

To develop and add parameters to a Lambda function, click on the service drop-down list, choose Lambda and click create function; name this new function Hello World and name your position appropriately.

14. How is the JSON document passed to the Lambda function in the input event object?

To accomplish this task, enter your code into the template window; your JSON document will then be passed directly into the Lambda function via the input event object body.

15. What is the purpose of creating an API Gateway directly through a Lambda service?

Producing an API Gateway this way enables independent API development without forwarding requests to an internal back-end server.

16. What is the purpose of creating a mapping template for an HTTP 200 status code?

Creating a mapping template for HTTP 200 status codes allows administrators to map its value into an accurate message for return to clients.

17. What is a PI in AWS?

An API, or Application Programming Interface, is a software intermediate tree that facilitates communication between applications or databases and devices, allowing quick and efficient exchange between services and databases.

18. What are the features of the AWS API Gateway?

The AWS API Gateway’s features make seamless integration and flexibilityan indispensable asset to developers looking to develop applications on cloud servers.

19. What are the two types of developers who use the Amazon AWS Gateway?

Amazon AWS Gateway can be utilised by two types of developers: API developers and app developers; developers create and deploy APIs necessary for the functionality of an API gateway, while app developers focus on app creation using AWS services such as FPS or Elastic Beanstalk.

20. What is the best way to create a REST API using AWS?

AWS Lambda and API Gateway offer excellent options for building REST APIs on AWS.

21. How do I access the AWS Lambda console?

You can access your AWS Lambda console by signing into your account and selecting Lambda service under the Compute section in the AWS Management Console.

22. What is the default test event for Lambda functions?

A default test event exists, and users can open it by selecting “select a test event” in the dialogue box or opening a drop-down list followingthe test option in the code editor.

23. How do users create the API Gateway for their Lambda function?

Once their Lambda function has been created, users should establish their corresponding API Gateway using the AWS Lambda console’s networking and content delivery service list by selecting “API Gateway”.

24. How do users test the API using various tools?

Users can test an API using various tools, including Curl or Postman; the author uses a loop for this tutorial.

25. How do users deploy their rest API in their created app?

To deploy the rest of the API in an app created, click on the Actions drop-down menu and choose Deploy API in the deployment Stage drop-down.

26. How do you grant API gateway permission to invoke the lambda function?

After saving, an “Add Permission to Lambda Function” pop-up will appear, prompting you to grant the API Gateway permission to invoke the lambda function you just kept and clicking OK grants these necessary rights.

27. How are microservices in Amazon’s architecture connected?

Amazon’s microservices connect via HTTPS and use standard authentication and authorisation services across services to interoperate seamlessly.

28. What is the primary technology stack for an API?

An API includes several technologies in its basic technology stack, these are clients, the internet or network, an API server, backend databases or data stores and front-end servers with API gateway capabilities.

29. What are some of the capabilities of an API gateway?

An API gateway offers API keys for developers while offering usage throttling and modelling, SDK generation, DDoS protection and more.

30. What does AWS offer the API Gateway?

AWS’ API gateway product fits perfectly for serverless development requirements such as API critical procurement for developers, usage tiering throttling, modelling capabilities, SDK generation and DDoS protection capabilities and much more.

31. What is a serverless web application?

A serverless web app is an architectural pattern in which modern JavaScript frameworks such as React, Vue or Angular are utilised as web application front ends to represent web apps on S3, with static content stored there and S3 being used as its server; AWS Lambda handles business logic which API Gateway or other services may trigger.

32. What is the Open API Specification?

Open API Specification is a popular method for specifying API and API definitions, used both directly to create APIs and when setting up serverless apps using SAM, which automatically generates Swagger text behind the scenes.

33. What are the stages in API Gateway?

API Gateway offers various settings, such as prod and stage stages, which can be configured for specific HTTP calls, such as logging, tracing, stage variables, SDK generation, document history and canaries, etc.

34. What is a WebSocket API?

A WebSocket API allows the creation of bi-directional total duplex web sockets using JavaScript code capable of bi-directional full duplex communication over persistent TCP connections and building real-time two-way communication applications like chat apps or streaming dashboards.

35. How do APIs facilitate communication between applications?

APIs help applications communicate by offering an easily understood standardised interface for exchanging data while specifying its format and structure.

36. How do APIs enable developers to reuse code and functionality?

APIs enable developers to reuse code and functionality by providing an open interface that other applications can utilise to access data or services, providing developers with more opportunities to reuse their work and that developed elsewhere.

37. How do APIs help to create a user interface?

APIs help create user interfaces by offering a standardised means of accessing data and services that enable applications to interact directly with their target audiences.

38. What is the difference between a UI and an API?

Aninterface provides users with interaction with an app or service, while an API acts as an intermediary that connects different apps or services for communication purposes.

39. What are SDKs?

SDKs, or software development kits, provide applications with programming tools for making call requests to APIs.

40. How do APIs enable communication between applications?

APIs facilitate communication among different apps by offering standardised ways for them to interact and exchange data with each other.

Put on multiple-choice tests to assess how well you understand this material.

41. What is the final step in creating a Lambda function?

Returning the response object

Converting the object into a string

Setting up the HTTP response object

Copying and pasting the code

42. What message is added to the response object?

“Hello from Lambda land.”

“Transaction successful.”

“Error occurred.”

“Processing transaction.”

43. What is the content type on the headers?

Application JSON

text/plain

application/XML

image/jpeg

44. What is the first step in creating a Lambda function?

Parsing out the query exchange parameters

Constructing the response body

Adding a separate field at the bottom

Setting up the HTTP response object