- A
Have all services call each other directly via synchronous API calls
Why wrong: Direct synchronous calls create tight coupling — if the downstream service is slow or fails, it directly impacts the upstream caller.
- B
Use Amazon SQS or Amazon SNS between services to decouple them
Message queues and event buses create loose coupling — producers write to the queue and consumers process independently. Components can be updated, scaled, or fail without directly affecting each other.
- C
Deploy all application components on a single large EC2 instance
Why wrong: A monolith on a single instance is the most tightly coupled architecture — all components fail together and can't scale independently.
- D
Use a single shared database for all microservices
Why wrong: A shared database creates tight coupling through the data layer — services become interdependent through shared schema and transactions.
CLF-C02 Cloud Concepts Practice Question
This CLF-C02 practice question tests your understanding of cloud concepts. 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 architect is designing a new system on AWS. They want to implement the Well-Architected Framework principle of 'loosely coupled components.' Which architecture pattern best achieves this?
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 SQS or Amazon SNS between services to decouple them
Option B is correct because Amazon SQS (message queue) and Amazon SNS (pub/sub) enable asynchronous communication between services, allowing them to operate independently without direct dependencies. This decoupling aligns with the Well-Architected Framework's principle of loosely coupled components, as services can fail, scale, or be updated without impacting others.
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.
- ✗
Have all services call each other directly via synchronous API calls
Why it's wrong here
Direct synchronous calls create tight coupling — if the downstream service is slow or fails, it directly impacts the upstream caller.
- ✓
Use Amazon SQS or Amazon SNS between services to decouple them
Why this is correct
Message queues and event buses create loose coupling — producers write to the queue and consumers process independently. Components can be updated, scaled, or fail without directly affecting each other.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Deploy all application components on a single large EC2 instance
Why it's wrong here
A monolith on a single instance is the most tightly coupled architecture — all components fail together and can't scale independently.
- ✗
Use a single shared database for all microservices
Why it's wrong here
A shared database creates tight coupling through the data layer — services become interdependent through shared schema and transactions.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often assume synchronous API calls (Option A) are simpler and sufficient for decoupling, but the Well-Architected Framework specifically requires asynchronous messaging (SQS/SNS) to achieve true loose coupling.
Detailed technical explanation
How to think about this question
Under the hood, Amazon SQS uses a pull-based model where consumers poll the queue, enabling at-least-once delivery and horizontal scaling of consumers independently. Amazon SNS uses a push-based model with fan-out to multiple subscribers (e.g., SQS queues, Lambda, HTTP endpoints), allowing one event to trigger multiple decoupled workflows. In a real-world e-commerce scenario, an order service can publish to SNS, which fans out to an inventory SQS queue and a shipping SQS queue, ensuring order processing continues even if the shipping service is temporarily unavailable.
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.
TExam Day Tips
- 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
An e-commerce site experiences heavy traffic on Black Friday and near-zero traffic during off-peak weeks. Rather than provisioning permanent large VMs, the team uses auto-scaling groups that add capacity automatically under load and reduce it overnight. Questions like this test whether you understand elasticity, availability zones, and cloud compute scaling patterns.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
- →
Cloud Concepts — study guide chapter
Learn the concepts, then practise the questions
- →
Cloud Concepts practice questions
Targeted practice on this topic area only
- →
All CLF-C02 questions
1,024 questions across all exam domains
- →
AWS Certified Cloud Practitioner CLF-C02 study guide
Full concept coverage aligned to exam objectives
- →
CLF-C02 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related CLF-C02 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Cloud Concepts practice questions
Practise CLF-C02 questions linked to Cloud Concepts.
Security and Compliance practice questions
Practise CLF-C02 questions linked to Security and Compliance.
Cloud Technology and Services practice questions
Practise CLF-C02 questions linked to Cloud Technology and Services.
Billing, Pricing, and Support practice questions
Practise CLF-C02 questions linked to Billing, Pricing, and Support.
AWS shared responsibility model practice questions
Practise CLF-C02 questions linked to AWS shared responsibility model.
AWS IAM practice questions
Practise CLF-C02 questions linked to AWS IAM.
AWS pricing practice questions
Practise CLF-C02 questions linked to AWS pricing.
AWS support plans practice questions
Practise CLF-C02 questions linked to AWS support plans.
AWS S3 practice questions
Practise CLF-C02 questions linked to AWS S3.
AWS EC2 practice questions
Practise CLF-C02 questions linked to AWS EC2.
Practice this exam
Start a free CLF-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 CLF-C02 question test?
Cloud Concepts — This question tests Cloud Concepts — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Use Amazon SQS or Amazon SNS between services to decouple them — Option B is correct because Amazon SQS (message queue) and Amazon SNS (pub/sub) enable asynchronous communication between services, allowing them to operate independently without direct dependencies. This decoupling aligns with the Well-Architected Framework's principle of loosely coupled components, as services can fail, scale, or be updated without impacting others.
What should I do if I get this CLF-C02 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
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 →
Keep practising
More CLF-C02 practice questions
- A company publishes a message each time a new product is added to its catalogue. Three services need to receive this mes…
- A media company stores frequently accessed video thumbnails in Amazon S3. The thumbnails are read multiple times every d…
- A company needs a service to translate domain names (like www.example.com) into IP addresses, check the health of their…
- A startup runs an application on AWS and receives a monthly bill that charges exactly for the number of compute hours us…
- A financial institution runs its core banking application on-premises due to regulatory requirements. It has connected i…
- A company wants to run a MySQL database in AWS without managing database software installation, applying patches, settin…
Last reviewed: Jun 11, 2026
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.
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.