SAP-C02 Design for New Solutions Practice Question
A startup is building a serverless photo-sharing application on AWS. Users upload photos via a web app, which stores them in Amazon S3. Each upload triggers an AWS Lambda function that creates a thumbnail and stores it in another S3 bucket. The application is expected to have unpredictable traffic patterns. The startup wants to minimize costs and operational overhead while ensuring the thumbnail generation completes reliably. Which solution should a Solutions Architect recommend?
⚠ Common exam trap
SAP-C02 often tests whether candidates over-engineer solutions by inserting SQS or ECS when a direct S3-to-Lambda integration already meets the reliability and cost requirements — the trap is choosing the more complex option thinking it is more robust.
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
✓
Configure S3 event notifications to invoke a Lambda function directly upon upload to generate thumbnails.
S3 event notifications can invoke a Lambda function directly on each object-created event, giving a fully serverless, event-driven pipeline with no polling, no servers to manage, and pay-per-invocation pricing that scales automatically with unpredictable traffic. This satisfies the reliability, cost, and operational-overhead requirements in one step.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Use Amazon ECS with Fargate to run a container that processes S3 events and generates thumbnails.
Why it's wrong here
Using Amazon ECS with Fargate introduces unnecessary container orchestration overhead for a simple event-driven thumbnail task, whereas the requirement for minimal operational overhead and unpredictable traffic is better served by a fully managed, event-driven AWS Lambda function that scales automatically to zero when idle. This option is tempting because Fargate removes server management and can handle long-running or resource-intensive image processing workloads that exceed Lambda's 15-minute timeout or memory limits, making it correct for batch processing or high-resolution thumbnail generation.
- ✗
Upload to S3, send a message to an SQS queue, and have a Lambda function poll the queue to generate thumbnails.
Why it's wrong here
SQS decouples the upload from processing, yet the stem already has S3 event notifications invoking Lambda directly, so the queue adds a component without changing reliability. It is tempting because SQS is the right choice when you must buffer bursts, retry failed batches or fan out to multiple consumers.
- ✗
Use an Auto Scaling group of EC2 instances to poll S3 for new uploads and generate thumbnails.
Why it's wrong here
Polling S3 from EC2 instances requires continuously running servers, so you pay for idle capacity during quiet periods and manage patching, scaling and failure handling. It is tempting because EC2 suits steady, predictable workloads needing full OS control, but S3 event notifications to Lambda already deliver the trigger without polling.
- ✓
Configure S3 event notifications to invoke a Lambda function directly upon upload to generate thumbnails.
Why this is correct
S3 event notifications invoking Lambda directly provide native, event-driven thumbnail generation with no polling or servers, scaling automatically with unpredictable upload volumes. This satisfies the reliability requirement while minimising cost and operational overhead, since AWS manages invocation and retries.
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
Related to this question
About these practice questions
This SAP-C02 question is part of Courseiva's 984-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Amazon Web Services exam blueprint
This SAP-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 SAP-C02 exam.