AWS DVA-C02 Drill: Git Merge Conflicts - CodeCommit Resolution Strategies

Jeff’s Note

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Jeff’s Note

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“Unlike generic exam dumps, ADH analyzes this scenario through the lens of a Real-World Lead Developer.”

“For DVA-C02 candidates, the confusion often lies in overthinking Git workflows and introducing unnecessary complexity. In production, this is about knowing exactly which Git commands and CodeCommit features minimize developer overhead while maintaining code integrity. Let’s drill down.”

The Certification Drill

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Scenario

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TechFlow Analytics runs a data visualization platform with a CI/CD pipeline built on AWS CodePipeline. Their source code resides in AWS CodeCommit repositories. Last sprint, a backend engineer named Maria was implementing a new API endpoint in her feature branch feature/analytics-v2. She branched off from main three weeks ago but forgot to regularly sync with the mainline.

Meanwhile, the team merged 47 commits into main, including database schema updates and configuration changes. When Maria attempted to merge her work yesterday, CodeCommit flagged 12 merge conflicts across 5 files.

The Requirement

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Resolve the merge conflicts in Maria’s feature branch using the approach that requires the LEAST development effort while maintaining proper version control practices.

The Options

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• A) Clone the repository locally. Create a completely new branch from the current main. Manually reapply all changes from the feature branch to the new branch.
• B) Create a new feature branch from the current state of main. Use git cherry-pick to selectively apply commits from the old feature branch.
• C) Use the CodeCommit Commit Visualizer view to identify when conflicting changes were introduced. Resolve conflicts directly through the AWS Console interface.
• D) Cancel the current merge attempt. Execute git rebase main on the feature branch, then resolve conflicts during the rebase process.

Google adsense

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Correct Answer

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C) Use the Commit Visualizer view to compare the commits when a feature was added. Fix the merge conflicts.

Quick Insight: The Developer Efficiency Imperative

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For DVA-C02, this tests your understanding of CodeCommit’s native conflict resolution tools versus manual Git operations. The exam wants you to recognize that AWS provides built-in visual tools specifically designed to minimize context-switching and terminal work. The trap? Developers often default to CLI-based workflows when AWS Console tools are more efficient for one-time conflict resolution.

Content Locked: The Expert Analysis

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You’ve identified the answer. But do you know the implementation details that separate a Junior from a Senior?

The Expert’s Analysis

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Correct Answer

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Option C

The Winning Logic

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The CodeCommit Console provides a Commit Visualizer that allows developers to:

1. Visually compare commit histories between branches in a graph view
2. Identify the exact commits that introduced conflicting changes
3. Resolve merge conflicts directly in the browser using the built-in merge conflict editor
4. Complete the merge operation without cloning the repository or using local Git commands

Why this minimizes effort:

• No local environment setup required - works entirely through AWS Console
• Visual diff interface shows conflict markers with side-by-side comparison
• One-click conflict resolution for simple conflicts (accept current/incoming changes)
• Immediate commit - changes are pushed directly to the remote branch
• No Git expertise required - the UI abstracts complex Git operations

For DVA-C02 candidates, AWS expects you to leverage managed service features over manual approaches. This aligns with the “Developer-Centric Tools” domain of the exam.

The Trap (Distractor Analysis)

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Why not Option A? Creating a new branch and manually reapplying changes is the highest effort approach:

• Requires cloning the entire repository
• Manual identification of all changes across potentially dozens of commits
• Risk of missing commits or introducing new bugs during manual transfer
• Multiple steps: create branch, identify changes, copy code, test, commit
• Violates the principle of preserving Git history

Why not Option B? Using git cherry-pick is technically sound but introduces unnecessary complexity:

• Still requires local repository clone
• Manual identification of commit SHAs to cherry-pick
• Potential for cherry-pick conflicts on each commit
• Higher cognitive load - must understand Git’s internal commit graph
• More time-consuming than direct conflict resolution
• Not leveraging AWS CodeCommit’s native features (key exam concept)

Why not Option D? Rebasing is a common Git practice but creates more work in this scenario:

• Requires local Git environment and CLI proficiency
• Rewrites commit history (creates new commit SHAs)
• With 47 commits on main, rebase will require resolving conflicts multiple times (once per conflicting commit)
• Risk of getting into a “rebase hell” with cascading conflicts
• Requires force-push afterward (dangerous in shared branches)
• More complex than a simple merge conflict resolution

The exam keyword here is “LEAST development effort” - this explicitly points to using the built-in AWS tooling.

The Technical Blueprint

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# What Option D would require (compare complexity):
git checkout feature/analytics-v2
git fetch origin
git rebase origin/main
# At this point, resolve conflicts in file1.py
git add file1.py
git rebase --continue
# Resolve conflicts in file2.py
git add file2.py
git rebase --continue
# ... potentially 12 more conflict resolutions
git push origin feature/analytics-v2 --force

# What Option C achieves through AWS Console:
# 1. Navigate to CodeCommit → Repositories → [Your Repo]
# 2. Click "Commits" → "Commit visualizer"
# 3. Select your feature branch
# 4. Click "Create pull request" or "Merge"
# 5. Use built-in conflict resolution editor
# 6. Click "Resolve conflicts" → "Commit merge"
# Done in 6 clicks, no CLI required

AWS CodeCommit Conflict Resolution API (for automation):

import boto3

codecommit = boto3.client('codecommit')

# Get merge conflicts
response = codecommit.get_merge_conflicts(
    repositoryName='techflow-analytics',
    sourceCommitSpecifier='feature/analytics-v2',
    destinationCommitSpecifier='main',
    mergeOption='THREE_WAY_MERGE'
)

# Resolve conflicts programmatically
response = codecommit.create_unreferenced_merge_commit(
    repositoryName='techflow-analytics',
    sourceCommitSpecifier='feature/analytics-v2',
    destinationCommitSpecifier='main',
    mergeOption='THREE_WAY_MERGE',
    conflictDetailLevel='LINE_LEVEL',
    conflictResolutionStrategy='ACCEPT_SOURCE'  # or manual resolution
)

The Comparative Analysis

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Key Exam Insight: When the question includes “LEAST development effort” + mentions an AWS service by name (CodeCommit), the answer will leverage that service’s native features over generic Git commands.

Real-World Application (Practitioner Insight)

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Exam Rule

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“For the DVA-C02 exam, when you see ‘LEAST effort’ + ‘CodeCommit’ + ‘merge conflicts’, always choose the AWS Console visual tools (Commit Visualizer, Pull Request UI) over CLI-based Git operations.”

Real World

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“In actual development teams, the approach depends on team culture and conflict complexity:

• Small teams, simple conflicts: CodeCommit Console (as per exam answer) works perfectly
• Large teams, complex conflicts: Many orgs use git rebase workflow with protected branch policies because:
  • Maintains linear history (easier for git bisect debugging)
  • Developers have Git expertise and local IDE preferences
  • Automated CI checks run on each rebased commit
• Enterprise with junior developers: Pull Request workflows with automated conflict detection and assignment to senior reviewers

However, for the exam, AWS wants you to maximize use of AWS-managed features. In real projects with CodeCommit, I’d use:

1. Console for quick one-off conflicts (matches exam scenario)
2. CodeCommit Pull Requests with approval rules for team reviews
3. Rebase locally only when maintaining clean history is critical (e.g., open-source projects)

The exam tests your knowledge of AWS service capabilities, not Git best practices philosophy.”

Stop Guessing, Start Mastering

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Disclaimer

This is a study note based on simulated scenarios for the AWS DVA-C02 exam. Company names and scenarios are fictional. AWS service behaviors and best practices are based on current AWS documentation as of December 2025.