The answer is to clear the CodeBuild cache, as a corrupted or out-of-sync cache is the most likely cause of the NoClassDefFoundError. CodeBuild caches dependency directories like Maven’s local repository to speed up subsequent builds, but if that cache becomes stale or corrupted—for instance, after a dependency version update in pom.xml—the build will reference old or missing class files instead of re-downloading them, leading to the error even though the dependencies are declared. On the AWS Certified DevOps Engineer Professional DOP-C02 exam, this scenario tests your understanding of CodeBuild’s caching mechanism and how it can silently break dependency resolution, a common trap where candidates mistakenly blame S3 permissions or Git pull frequency. Remember the mnemonic: “Cache clash causes class crash”—when you see a missing class error despite correct pom.xml entries, always suspect the cache first.
DOP-C02 SDLC Automation Practice Question
This DOP-C02 practice question tests your understanding of sdlc automation. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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.
An organization uses AWS CodeBuild to compile a Java application. The buildspec.yml includes a pre_build phase that runs unit tests. Recently, the build started failing with 'NoClassDefFoundError' for certain test dependencies, even though the pom.xml includes them. The build environment uses an Amazon Linux 2 Docker image. What is the MOST likely cause?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The CodeBuild project has a cache that is corrupted or out of sync. Clear the build cache.
Option A is correct because CodeBuild caches dependency directories to speed up builds; a corrupted or stale cache can cause missing classes. Option B is wrong because CodeCommit pull frequency is unrelated. Option C is wrong because S3 bucket permissions affect artifact upload, not dependency resolution. Option D is wrong because Amazon Linux 2 includes Maven, but that would not cause a single class missing.
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.
✓
The CodeBuild project has a cache that is corrupted or out of sync. Clear the build cache.
Why this is correct
Cached dependencies may be stale or incomplete, leading to NoClassDefFoundError.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
The S3 bucket for artifacts has incorrect permissions. Update the bucket policy.
Why it's wrong here
Artifact permissions do not affect dependency classes at build time.
✗
The CodeCommit repository is not pulling the latest code. Add a webhook to trigger builds on push.
Why it's wrong here
The issue is with dependency resolution, not source code updates.
✗
The build environment does not have Maven installed. Install Maven in the buildspec.
Why it's wrong here
Amazon Linux 2 standard image includes Maven; missing Maven would cause different errors.
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 media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.
What to study next
Got this wrong? Here's your next step.
Identify which DOP-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.
SDLC Automation — This question tests SDLC Automation — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The CodeBuild project has a cache that is corrupted or out of sync. Clear the build cache. — Option A is correct because CodeBuild caches dependency directories to speed up builds; a corrupted or stale cache can cause missing classes. Option B is wrong because CodeCommit pull frequency is unrelated. Option C is wrong because S3 bucket permissions affect artifact upload, not dependency resolution. Option D is wrong because Amazon Linux 2 includes Maven, but that would not cause a single class missing.
What should I do if I get this DOP-C02 question wrong?
Identify which DOP-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: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
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 →
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.
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.
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.