DOP-C02 Resilient Cloud Solutions Practice Question
A company runs a microservices application on Amazon ECS with Fargate launch type. The application experiences intermittent failures when calling an external API. The errors are transient and usually resolve within a few seconds. How should the company improve resilience?
⚠ Common exam trap
DOP-C02 often tests the difference between scaling (more tasks) and resilience patterns (retries, backoff) — candidates pick 'increase tasks' because it sounds like high availability, but it does nothing for transient downstream errors.
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
✓
Implement retry logic with exponential backoff in the application code.
Transient errors from an external API are best handled with retry logic using exponential backoff and jitter. This allows the application to recover from temporary failures without overwhelming the downstream API, improving resilience without architectural changes.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Increase the timeout of the external API call to 60 seconds.
Why it's wrong here
Extending the timeout to 60 seconds holds connections open during transient faults, delaying retries and consuming task resources while the external API recovers. Timeouts suit slow-but-successful calls, not intermittent failures; resilience here needs retry with exponential backoff and jitter.
- ✓
Implement retry logic with exponential backoff in the application code.
Why this is correct
Transient external API failures resolve within seconds, so retrying with exponential backoff lets the application recover without overwhelming the dependency. This directly addresses the intermittent, short-lived errors described, unlike circuit breakers or timeouts that would abort calls rather than succeed on retry.
- ✗
Increase the number of tasks in the ECS service to handle failures.
Why it's wrong here
Adding ECS tasks scales capacity for request volume; it does nothing for outbound calls that fail transiently, since each task still hits the same failing API. Horizontal scaling is right when the service itself is the bottleneck, not when a downstream dependency intermittently errors.
- ✗
Use an Amazon SQS queue to decouple the API call from the application.
Why it's wrong here
An SQS queue decouples asynchronous producers from consumers, but the stem describes synchronous request-response calls to an external API, so queuing adds latency without retrying the failed call. SQS is correct for buffering work between internal components, not for transient downstream errors.
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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 DOP-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 DOP-C02 exam.