CV0-004 Deployment Practice Question
A company wants to deploy a Lambda function that processes objects uploaded to an S3 bucket. Which event trigger should be configured on the Lambda function?
⚠ Common exam trap
CompTIA Cloud+ often tests the misconception that SQS or CloudWatch Events are required to bridge S3 and Lambda, when in fact S3 can invoke Lambda directly via its event notification feature.
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
✓
S3 bucket event notification
S3 bucket event notifications can be configured to directly invoke a Lambda function when objects are uploaded. This is the native, serverless integration where S3 publishes an event (e.g., s3:ObjectCreated:Put) to Lambda, triggering the function automatically without any intermediary service.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
API Gateway
Why it's wrong here
API Gateway invokes Lambda in response to inbound HTTP requests, not S3 object-created events, so uploads would never trigger the function. It is tempting because it is a common Lambda trigger, and it would be correct when the function must serve a REST or HTTP API endpoint instead of processing bucket objects.
- ✗
CloudWatch Events
Why it's wrong here
CloudWatch Events (EventBridge) reacts to schedules or AWS service events it subscribes to, but S3 object creation is delivered through S3 event notifications, not this trigger. It is tempting because it can invoke Lambda on a schedule, and it would be correct for cron-style runs or event-pattern matching.
- ✓
S3 bucket event notification
Why this is correct
S3 bucket event notifications push records directly to Lambda when objects are created, satisfying the stem's requirement to process uploads automatically. This native integration invokes the function per object without polling, unlike scheduled or manual triggers. Configuring the notification on the bucket, filtered by event type, delivers the object metadata Lambda needs.
- ✗
SQS
Why it's wrong here
SQS queues messages for consumers to poll; it does not natively emit an event when an S3 object is created, so no trigger fires. It is tempting because SQS decouples producers from Lambda, and it would be correct when the function should process messages placed on a queue rather than react to S3 uploads.
Quick reference
AWS S3 Storage Class Comparison
| Storage Class | Min Duration | Retrieval | Use Case |
|---|---|---|---|
| S3 Standard | None | Immediate | Frequently accessed data |
| S3 Standard-IA | 30 days | Immediate | Infrequent access, rapid retrieval |
| S3 One Zone-IA | 30 days | Immediate | Non-critical infrequent data |
| S3 Intelligent-Tiering | None | Immediate–hours | Unknown or changing access patterns |
| S3 Glacier Instant | 90 days | Milliseconds | Archive with instant retrieval |
| S3 Glacier Flexible | 90 days | Minutes–hours | Archive, flexible retrieval |
| S3 Glacier Deep Archive | 180 days | Hours | Long-term compliance archive |
Go deeper
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This CV0-004 practice question is part of Courseiva's free CompTIA 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 CV0-004 exam.