Question 1mediummultiple choice
Full question →mediummultiple choiceObjective-mapped
A development team is building a serverless application that processes image uploads to Amazon S3. The application needs to automatically generate a thumbnail version of each uploaded image and store it in a separate S3 bucket. The team wants to minimize operational overhead and only pay for the compute time used during thumbnail generation. Which AWS service should the team use to execute the thumbnail generation code in response to S3 upload events?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Distractor review
Amazon EC2 Auto Scaling group
EC2 Auto Scaling helps manage instance capacity but requires running servers even when idle; it is not natively triggered by S3 events without additional setup and does not offer pay-per-execution billing.
B
Best answer
AWS Lambda
AWS Lambda is a serverless compute service that can be triggered directly by S3 events. It runs code only when invoked, scales automatically, and bills only for the compute time used, meeting all the stated requirements.
C
Distractor review
Amazon ECS with Fargate
Amazon ECS with Fargate runs containers without managing servers, but it is not designed for event-driven invocation in the same way as Lambda. Typically, an intermediary service (like Lambda) would be needed to trigger a container task, and you pay for running containers even while waiting for work.
D
Distractor review
Amazon Elastic Beanstalk
Elastic Beanstalk is a PaaS service that automates deployment and scaling of applications, but it requires running environments (EC2 instances) that incur costs even when idle. It is not an event-driven compute service and does not provide pay-per-execution billing.
Common exam trap
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Technical deep dive
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
- Use explanations to understand the rule behind the answer.
TExam Day Tips
- Underline the problem statement mentally.
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
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More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
Question 1
A developer needs to launch a test server for a new application prototype. The developer logs into the AWS Management Console, selects an Amazon EC2 instance type, configures the security group, and starts the instance. The instance is running within two minutes, and the developer did not need to submit a formal request to the company's IT procurement team or wait for approval from a cloud administrator. Which essential characteristic of cloud computing does this scenario best demonstrate?
Question 2
A solutions architect is planning a new web application on AWS. The workload will include 3 Amazon EC2 instances (t3.medium) running 24/7, an Application Load Balancer, and an Amazon RDS for MySQL db.t3.small database. The architect needs to estimate the monthly cost for the first year, considering different purchasing options (On-Demand, 1-year All Upfront Reserved Instance, and Compute Savings Plan). Which AWS tool should the architect use to create this estimate?
Question 3
A company's development team frequently needs temporary test environments. A developer can log into the AWS Management Console, select an Amazon EC2 instance type, configure storage, and launch the instance within minutes without any interaction with the IT infrastructure team. This capability is an example of which essential characteristic of cloud computing?
Question 4
A company's finance team needs to analyze AWS spending in detail. They require a report that includes hourly cost data for each AWS service, each individual resource (e.g., a specific EC2 instance), and any cost allocation tags applied. The team plans to export this data to an Amazon S3 bucket and then import it into a custom business intelligence (BI) analytics dashboard. Which AWS tool should the finance team use to generate this level of detailed cost data?
Question 5
A company uses AWS for its development environment. The finance team wants to set a monthly budget of $10,000. They want to receive an email notification when the actual costs reach 80% of the budget ($8,000) and again when costs exceed the budget. The team needs a managed AWS service that can automatically send these alerts without requiring custom code or third-party tools. Which AWS service should the team use?
Question 6
A company uses AWS Organizations to manage multiple accounts. The security team needs to enforce a policy that restricts SSH access (port 22) from the internet (0.0.0.0/0) in all VPCs across all accounts. The team wants to centrally define the allowed rules and automatically apply them to newly created VPCs and security groups, while also automatically remediating any existing non-compliant security groups. Which AWS service should the team use?
FAQ
Questions learners often ask
What does this CLF-C02 question test?
Read the scenario before looking for a memorised answer.
What is the correct answer to this question?
The correct answer is: AWS Lambda — The requirement is for an event-driven, serverless compute service that triggers on S3 upload events and runs only when needed. AWS Lambda is designed for exactly this use case: it runs code in response to events such as S3 object creation, and charges only for the compute time consumed. No servers to manage, and it scales automatically. Amazon EC2 Auto Scaling requires managing instances and is not event-triggered in this direct way. Amazon ECS with Fargate reduces server management but still requires container orchestration and is less straightforward for simple S3 event triggers. Amazon Elastic Beanstalk provides a PaaS environment but is not primarily event-driven and includes ongoing costs even when idle.
What should I do if I get this CLF-C02 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
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