CLF-C02 Cloud Technology and Services Practice Question
A company is building a serverless web application using AWS Lambda for compute. The application needs to expose RESTful API endpoints that allow users to perform CRUD operations on a database. The API must support authentication using API keys, throttle requests to prevent abuse, and validate incoming request payloads before they reach the Lambda functions. The company wants a fully managed service that handles these API management tasks and integrates directly with AWS Lambda. Which AWS service should the company use?
⚠ Common exam trap
Test-takers frequently confuse Application Load Balancer (ALB) with API Gateway because both can invoke Lambda, but ALB lacks the API management features (API keys, throttling, payload validation) that are explicitly required in the question.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Amazon API Gateway
Amazon API Gateway is a fully managed service that handles RESTful API creation, authentication via API keys, request throttling to prevent abuse, and request payload validation before invoking AWS Lambda functions. It integrates natively with Lambda, making it the ideal choice for serverless web applications requiring CRUD operations with built-in API management.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Amazon CloudFront
Why it's wrong here
Amazon CloudFront is a content delivery network (CDN) that caches content at edge locations. While it can be used as a front end for APIs, it does not provide built-in API key authentication, request validation, or throttling capabilities specifically for API management tasks. CloudFront is optimized for delivering static and dynamic content with low latency, not for managing APIs.
When this WOULD be correct
A company needs to deliver static and dynamic web content globally with low latency, and wants to cache API responses at edge locations to reduce load on backend servers. The question would ask for a service to accelerate content delivery and protect against DDoS attacks, not for API management.
- ✓
Amazon API Gateway
Why this is correct
Amazon API Gateway is a fully managed service designed to handle all aspects of API management, including authentication (API keys, IAM, Cognito), request throttling, rate limiting, request validation, and direct integration with AWS Lambda. It is the correct choice for exposing Lambda-based serverless applications as RESTful APIs.
- ✗
Application Load Balancer
Why it's wrong here
An Application Load Balancer (ALB) can route HTTP/S traffic to Lambda functions as targets, but it does not provide API key authentication, request payload validation, or rate limiting. ALB is a load balancing service, not an API management service. It lacks the built-in API lifecycle features that API Gateway offers.
When this WOULD be correct
An ALB would be correct when the application uses container-based compute (e.g., ECS/EKS) or EC2 instances, and needs to distribute incoming HTTP traffic across multiple targets with path-based routing, but does not require API key management or request validation.
- ✗
AWS Step Functions
Why it's wrong here
AWS Step Functions is a serverless workflow orchestration service that lets you coordinate multiple AWS services into a state machine. It is not designed to expose external APIs or handle authentication, throttling, or request validation. It works behind the scenes, not as an API endpoint.
When this WOULD be correct
A company needs to coordinate multiple AWS Lambda functions in a sequence or parallel workflow, with error handling and retries, for a multi-step business process. Step Functions would be the correct service to define and execute that state machine.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The CLF-C02 exam frequently reuses these exact scenarios with slightly different constraints.
✓Amazon API GatewayCorrect answer▾
Why this is correct
Amazon API Gateway is a fully managed service designed to handle all aspects of API management, including authentication (API keys, IAM, Cognito), request throttling, rate limiting, request validation, and direct integration with AWS Lambda. It is the correct choice for exposing Lambda-based serverless applications as RESTful APIs.
✗Amazon CloudFrontWrong answer — click to see why▾
Why this is wrong here
Amazon CloudFront is a content delivery network (CDN) that caches and distributes content at edge locations; it does not provide API management features like authentication, throttling, or request validation, nor does it integrate directly with Lambda for RESTful API endpoints.
★ When this WOULD be the correct answer
A company needs to deliver static and dynamic web content globally with low latency, and wants to cache API responses at edge locations to reduce load on backend servers. The question would ask for a service to accelerate content delivery and protect against DDoS attacks, not for API management.
Why candidates choose this
Candidates may confuse CloudFront's ability to serve API content (e.g., via Lambda@Edge) with full API management capabilities, overlooking that CloudFront lacks native API key authentication, request validation, and throttling features.
✗Application Load BalancerWrong answer — click to see why▾
Why this is wrong here
Application Load Balancer (ALB) does not provide API key authentication, request throttling, or request validation. It is a Layer 7 load balancer for HTTP/HTTPS traffic, not a fully managed API management service.
★ When this WOULD be the correct answer
An ALB would be correct when the application uses container-based compute (e.g., ECS/EKS) or EC2 instances, and needs to distribute incoming HTTP traffic across multiple targets with path-based routing, but does not require API key management or request validation.
Why candidates choose this
Candidates may confuse ALB's ability to route HTTP requests and integrate with Lambda as a target with the full API management features of API Gateway, overlooking the specific requirements for authentication, throttling, and validation.
✗AWS Step FunctionsWrong answer — click to see why▾
Why this is wrong here
AWS Step Functions is a serverless orchestration service for coordinating multiple AWS services into workflows, not for managing RESTful APIs. It does not provide API key authentication, request throttling, or payload validation for HTTP endpoints.
★ When this WOULD be the correct answer
A company needs to coordinate multiple AWS Lambda functions in a sequence or parallel workflow, with error handling and retries, for a multi-step business process. Step Functions would be the correct service to define and execute that state machine.
Why candidates choose this
Candidates may confuse Step Functions' ability to invoke Lambda functions with API management capabilities, or think that 'serverless' and 'workflow' imply it can handle API tasks like authentication and throttling.
Analysis generated from the official CLF-C02blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Quick reference
Cloud Service Model Comparison
| Model | You Manage | Provider Manages | Examples |
|---|---|---|---|
| IaaS | OS, runtime, apps, data | Hardware, hypervisor, networking | EC2, Azure VMs, GCP Compute Engine |
| PaaS | Apps and data | OS, runtime, middleware, hardware | Elastic Beanstalk, Azure App Service |
| SaaS | Data and settings only | Everything else | Microsoft 365, Salesforce, Workday |
| FaaS / Serverless | Function code only | Infra, scaling, runtime | Lambda, Azure Functions, Cloud Run |
| CaaS | Containers and apps | Kubernetes, OS, hardware | EKS, AKS, GKE |
Go deeper
Related to this question
About these practice questions
Courseiva writes every CLF-C02 question from scratch — 988 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This CLF-C02 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CLF-C02 exam.