Why API Gateway matters in AWS - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to show the main role of an API Gateway in a system.

AWS

An API Gateway acts as a [1] between clients and backend services.

Drag options to blanks, or click blank then click option'

Afrontend

Bdatabase

Cbridge

Dstorage

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing 'database' because it stores data, but API Gateway does not store data.

The API Gateway acts as a bridge that connects clients to backend services, managing requests and responses.

2fill in blank

medium

Complete the code to describe a key feature of API Gateway.

AWS

API Gateway helps to [1] incoming requests to protect backend services.

Drag options to blanks, or click blank then click option'

Aignore

Bfilter

Cduplicate

Ddelay

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing 'ignore' because it sounds like skipping, but API Gateway actively manages requests.

API Gateway filters incoming requests to allow only valid and authorized traffic to backend services.

3fill in blank

hard

Fix the error in the sentence about API Gateway's role in scaling.

AWS

API Gateway helps backend services by [1] the load from many client requests.

Drag options to blanks, or click blank then click option'

Aignoring

Bblocking

Cincreasing

Dbalancing

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing 'increasing' which would make load worse.

API Gateway balances the load by distributing client requests efficiently to backend services.

4fill in blank

hard

Fill both blanks to complete the sentence about API Gateway features.

AWS

API Gateway provides [1] and [2] to secure and monitor APIs.

Drag options to blanks, or click blank then click option'

Aauthentication

Bcaching

Cencryption

Dlogging

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing caching with security features.

API Gateway provides authentication to verify users and logging to monitor API usage.

5fill in blank

hard

Fill all three blanks to complete the sentence about API Gateway benefits.

AWS

API Gateway helps by [1] requests, [2] backend services, and [3] API versions.

Drag options to blanks, or click blank then click option'

Arouting

Bprotecting

Cmanaging

Dignoring

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing 'ignoring' which is opposite of what API Gateway does.

API Gateway routes requests to the right place, protects backend services, and manages different API versions.

Practice

1. What is the primary role of an API Gateway in a cloud system?

easy

A. It replaces the need for backend servers.

B. It stores all the data for backend services.

C. It acts as a single entry point to manage and route API requests.

D. It directly processes user interface rendering.

Solution

1. Step 1: Understand API Gateway's function

   API Gateway acts as a front door that receives all API calls and routes them to appropriate backend services.

2. Step 2: Compare options with this role

   Only It acts as a single entry point to manage and route API requests. describes this role correctly; others describe unrelated functions.

3. Final Answer:

   It acts as a single entry point to manage and route API requests. -> Option C

4. Quick Check:

   API Gateway = Single entry point [OK]

Hint: API Gateway is the front door, not the data store [OK]

Common Mistakes:

• Confusing API Gateway with database storage
• Thinking API Gateway replaces backend servers
• Assuming API Gateway handles UI rendering

2. Which of the following is the correct way to define an API Gateway endpoint in AWS?

easy

A. Create a Lambda function and call it directly from the client.

B. Use S3 bucket URL as the API endpoint.

C. Set up an EC2 instance and expose its IP as the API endpoint.

D. Configure an API Gateway resource and method, then integrate with backend.

Solution

1. Step 1: Recall AWS API Gateway setup

   API Gateway requires defining resources and methods that connect to backend services like Lambda or HTTP endpoints.

2. Step 2: Evaluate options

   Configure an API Gateway resource and method, then integrate with backend. correctly describes configuring API Gateway resources and methods. Others describe unrelated or incorrect setups.

3. Final Answer:

   Configure an API Gateway resource and method, then integrate with backend. -> Option D

4. Quick Check:

   API Gateway setup = resource + method + backend integration [OK]

Hint: API Gateway needs resource and method setup, not direct Lambda calls [OK]

Common Mistakes:

• Calling Lambda directly without API Gateway
• Using EC2 IP as API endpoint without API Gateway
• Confusing S3 URLs with API endpoints

3. Given this AWS API Gateway setup: a GET method integrated with a Lambda function that returns {"status": "ok"}, what will the client receive when calling the endpoint?

medium

A. {"status": "ok"}

B. An error because API Gateway cannot integrate with Lambda

C. Empty response with status 200

D. HTML page instead of JSON

Solution

1. Step 1: Understand API Gateway and Lambda integration

   API Gateway forwards the request to Lambda, which returns a JSON response {"status": "ok"}.

2. Step 2: Determine client response

   The client receives the Lambda output as JSON through API Gateway, so the response is {"status": "ok"}.

3. Final Answer:

   {"status": "ok"} -> Option A

4. Quick Check:

   Lambda output = client response via API Gateway [OK]

Hint: API Gateway passes Lambda output as response [OK]

Common Mistakes:

• Thinking API Gateway blocks Lambda responses
• Expecting empty or HTML response by default
• Confusing integration types

4. You configured an API Gateway method but clients receive 403 Forbidden errors. What is the most likely cause?

medium

A. The client is sending requests with wrong HTTP method.

B. The API Gateway resource policy denies access to clients.

C. The backend database is down.

D. The Lambda function code has syntax errors.

Solution

1. Step 1: Analyze 403 Forbidden meaning

   403 means access is denied, often due to permissions or resource policies.

2. Step 2: Match cause to API Gateway

   API Gateway resource policies can restrict client access, causing 403 errors. Lambda errors or backend issues usually cause 500 errors, and wrong HTTP methods cause 405 errors.

3. Final Answer:

   The API Gateway resource policy denies access to clients. -> Option B

4. Quick Check:

   403 Forbidden = Access denied by policy [OK]

Hint: 403 means permission denied, check API Gateway policies [OK]

Common Mistakes:

• Confusing 403 with 500 or 405 errors
• Blaming Lambda code for 403 errors
• Ignoring API Gateway resource policies

5. You want to build a scalable system that handles thousands of API requests per second with security and monitoring. Why should you use AWS API Gateway instead of directly exposing backend services?

hard

A. API Gateway provides throttling, authentication, and detailed monitoring out of the box.

B. Direct backend exposure is faster and more secure than API Gateway.

C. API Gateway automatically writes backend code for you.

D. Backend services cannot handle API requests without API Gateway.

Solution

1. Step 1: Identify API Gateway features for scalability and security

   API Gateway offers throttling to limit request rates, authentication to secure access, and monitoring to track usage and errors.

2. Step 2: Compare with direct backend exposure

   Directly exposing backend services lacks these managed features, making scaling and security harder.

3. Step 3: Evaluate incorrect options

   Direct backend exposure is faster and more secure than API Gateway. is false because direct exposure is less secure. API Gateway automatically writes backend code for you. is false; API Gateway does not write backend code. Backend services cannot handle API requests without API Gateway. is false; backend can handle requests but less efficiently.

4. Final Answer:

   API Gateway provides throttling, authentication, and detailed monitoring out of the box. -> Option A

5. Quick Check:

   API Gateway = security + scaling + monitoring [OK]

Hint: API Gateway adds security and scaling features easily [OK]

Common Mistakes:

• Assuming direct backend is more secure
• Thinking API Gateway writes backend code
• Believing backend cannot handle requests alone