- A
Use IAM for authentication, EC2 instances behind an ALB for the API, and DynamoDB for the database.
Why wrong: IAM is not a user authentication service; EC2 instances are not serverless.
- B
Use Amazon Cognito for authentication, API Gateway with Lambda for the API, and Amazon DynamoDB for the database.
All services are serverless, fully managed, and scale automatically; DynamoDB is NoSQL.
- C
Use Amazon Cognito for authentication, API Gateway with Lambda for the API, and Amazon RDS for the database.
Why wrong: RDS is a relational database, not NoSQL; it also requires provisioning and scaling management.
- D
Use Amazon Cognito for authentication, API Gateway with Lambda for the API, and Amazon S3 for the database.
Why wrong: S3 is object storage, not a database; not suitable for typical CRUD operations.
Quick Answer
The correct solution is to use Amazon Cognito for authentication, API Gateway with Lambda for the REST API, and Amazon DynamoDB for the NoSQL database. This combination delivers a fully serverless backend for a mobile app because Cognito handles user sign-up and sign-in, API Gateway and Lambda process API requests without provisioning servers, and DynamoDB provides a fully managed NoSQL database that scales automatically with unpredictable traffic, minimizing costs by charging only for actual usage. On the AWS Certified Solutions Architect Professional SAP-C02 exam, this scenario tests your ability to match serverless services to specific workload requirements, often appearing as a straightforward trap where options include relational databases like RDS or compute instances like EC2. A common mistake is choosing S3 for database needs, but S3 is an object store, not suited for transactional data access. Memory tip: “CAL-D” — Cognito, API Gateway, Lambda, DynamoDB — the four pillars of a serverless mobile backend.
SAP-C02 Design for New Solutions Practice Question
This SAP-C02 practice question tests your understanding of design for new solutions. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A company wants to build a serverless backend for a mobile application. The backend provides user authentication, a REST API for data access, and stores data in a NoSQL database. The company expects the application to have unpredictable traffic, and wants to minimize costs. Which solution should a Solutions Architect recommend?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"minimum / minimize"Why it matters: Asks for the least resource use — fewest addresses, smallest subnet, lowest overhead. Eliminate over-provisioned options even if they would technically work.
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
Use Amazon Cognito for authentication, API Gateway with Lambda for the API, and Amazon DynamoDB for the database.
Option B is correct because Cognito provides authentication, API Gateway + Lambda provides serverless API, and DynamoDB is a NoSQL database that scales automatically. Option A is wrong because RDS is relational, not NoSQL. Option C is wrong because EC2 instances are not serverless. Option D is wrong because S3 is not a database; it can store data but not suitable for transactional data access.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
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 IAM for authentication, EC2 instances behind an ALB for the API, and DynamoDB for the database.
Why it's wrong here
IAM is not a user authentication service; EC2 instances are not serverless.
- ✓
Use Amazon Cognito for authentication, API Gateway with Lambda for the API, and Amazon DynamoDB for the database.
Why this is correct
All services are serverless, fully managed, and scale automatically; DynamoDB is NoSQL.
Clue confirmation
The clue word "minimum / minimize" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Use Amazon Cognito for authentication, API Gateway with Lambda for the API, and Amazon RDS for the database.
Why it's wrong here
RDS is a relational database, not NoSQL; it also requires provisioning and scaling management.
- ✗
Use Amazon Cognito for authentication, API Gateway with Lambda for the API, and Amazon S3 for the database.
Why it's wrong here
S3 is object storage, not a database; not suitable for typical CRUD operations.
Common exam traps
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.
Detailed technical explanation
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.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A startup's cloud architect reviews their monthly bill and notices costs are higher than expected for a long-running batch job. Switching from on-demand instances to Reserved Instances — or using Spot/Preemptible VMs — can reduce compute costs by up to 72 %. Questions like this test whether you understand the tradeoffs between commitment, flexibility, and cost across cloud pricing models.
What to study next
Got this wrong? Here's your next step.
Identify which SAP-C02 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
- →
Design for New Solutions — study guide chapter
Learn the concepts, then practise the questions
- →
Design for New Solutions practice questions
Targeted practice on this topic area only
- →
All SAP-C02 questions
1,746 questions across all exam domains
- →
AWS Certified Solutions Architect Professional SAP-C02 study guide
Full concept coverage aligned to exam objectives
- →
SAP-C02 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related SAP-C02 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Design Solutions for Organizational Complexity practice questions
Practise SAP-C02 questions linked to Design Solutions for Organizational Complexity.
Design for New Solutions practice questions
Practise SAP-C02 questions linked to Design for New Solutions.
Continuous Improvement for Existing Solutions practice questions
Practise SAP-C02 questions linked to Continuous Improvement for Existing Solutions.
Accelerate Workload Migration and Modernization practice questions
Practise SAP-C02 questions linked to Accelerate Workload Migration and Modernization.
SAA-C03 VPC practice questions
Practise SAP-C02 questions linked to SAA-C03 VPC.
SAA-C03 S3 lifecycle policy questions
Practise SAP-C02 questions linked to SAA-C03 S3 lifecycle policy questions.
SAA-C03 RDS Multi-AZ questions
Practise SAP-C02 questions linked to SAA-C03 RDS Multi-AZ questions.
SAA-C03 IAM policy practice questions
Practise SAP-C02 questions linked to SAA-C03 IAM policy.
SAA-C03 Route 53 failover questions
Practise SAP-C02 questions linked to SAA-C03 Route 53 failover questions.
SAA-C03 CloudFront practice questions
Practise SAP-C02 questions linked to SAA-C03 CloudFront.
SAA-C03 NAT gateway questions
Practise SAP-C02 questions linked to SAA-C03 NAT gateway questions.
SAA-C03 VPC endpoint questions
Practise SAP-C02 questions linked to SAA-C03 VPC endpoint questions.
Practice this exam
Start a free SAP-C02 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this SAP-C02 question test?
Design for New Solutions — This question tests Design for New Solutions — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Use Amazon Cognito for authentication, API Gateway with Lambda for the API, and Amazon DynamoDB for the database. — Option B is correct because Cognito provides authentication, API Gateway + Lambda provides serverless API, and DynamoDB is a NoSQL database that scales automatically. Option A is wrong because RDS is relational, not NoSQL. Option C is wrong because EC2 instances are not serverless. Option D is wrong because S3 is not a database; it can store data but not suitable for transactional data access.
What should I do if I get this SAP-C02 question wrong?
Identify which SAP-C02 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Are there clue words in this question I should notice?
Yes — watch for: "minimum / minimize". Asks for the least resource use — fewest addresses, smallest subnet, lowest overhead. Eliminate over-provisioned options even if they would technically work.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Last reviewed: Jun 20, 2026
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.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.