AWS DVA-C02 Drill: Deploying Serverless Applications - The SAM Packaging Sequence

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 proper SAM deployment sequencing and artifact packaging. In production, this means knowing exactly how to package your Lambda code and transform your SAM template so the deployment process automates seamlessly through CloudFormation. Let’s drill down.

The Certification Drill (Simulated Question)

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Scenario

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FinTech startup HorizonPay is developing a serverless payment processing application built on AWS Lambda using the AWS Serverless Application Model (SAM). The development team is preparing to deploy their SAM-based application to an AWS environment. They aim to follow best practices to ensure a smooth, repeatable deployment pipeline.

The Requirement:

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Determine the correct order of steps HorizonPay’s developers should take to build, package, and deploy their SAM application successfully.

The Options

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  - A) 1. Build the SAM template on an Amazon EC2 instance. 2. Package the SAM template onto Amazon EBS storage. 3. Deploy the SAM template from Amazon EBS.
  - B) 1. Build the SAM template locally. 2. Package the SAM template onto Amazon S3. 3. Deploy the SAM template from Amazon S3.
  - C) 1. Build the SAM template locally. 2. Deploy the SAM template from Amazon S3. 3. Package the SAM template for use.
  - D) 1. Build the SAM template locally. 2. Package the SAM template from AWS CodeCommit. 3. Deploy the SAM template to CodeCommit.

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Correct Answer

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B

Quick Insight: The Developer Imperative

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• The SAM CLI workflow requires building your application locally (compiling dependencies, transpiling, etc.), packaging your deployment artifacts (uploading Lambda code and dependencies to a centrally accessible S3 bucket), then deploying via CloudFormation referencing that S3 location.
• The key is that packaging always uploads code artifacts to Amazon S3; deployment pulls from S3 to create/update CloudFormation stacks.

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 B

The Winning Logic

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• Build Locally: The sam build command compiles your application code and dependencies locally (or in your CI/CD environment), preparing the deployment package.
• Package to S3: The sam package command uploads your Lambda function code and other deployment artifacts (like layers) to an S3 bucket. It transforms your SAM template by replacing local references with the appropriate S3 object URLs.
• Deploy from S3: The sam deploy command creates or updates your CloudFormation stack using the packaged template located in S3, ensuring your Lambda functions and resources get deployed accurately.

This is the officially recommended SAM deployment workflow. The packaging step is mandatory because CloudFormation does not accept local artifacts; all code must be referenced from S3.

The Trap (Distractor Analysis)

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• Option A: Incorrect because Amazon EBS is a block storage service, not designed to host deployment artifacts for Lambda. Also, building on EC2 is not required or recommended over local or CI environments.
• Option C: Deploying before packaging is illogical—CloudFormation requires references to S3 objects, so deploying before packaging will fail.
• Option D: CodeCommit is a source code repository and not a deployment artifact store. Packaging or deploying directly from CodeCommit is not part of the SAM workflow and would require additional pipeline steps.

The Technical Blueprint

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# Typical SAM CLI commands to build, package, and deploy a serverless app
sam build                     # Builds dependencies and prepares artifacts locally
sam package \
  --s3-bucket my-horizonpay-bucket \
  --output-template-file packaged.yaml   # Uploads code to S3 and outputs transformed template
sam deploy \
  --template-file packaged.yaml \
  --stack-name HorizonPayAppStack \
  --capabilities CAPABILITY_IAM          # Deploys CloudFormation stack using S3 references

The Comparative Analysis

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Real-World Application (Practitioner Insight)

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Exam Rule

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“For the exam, always pick packaging to S3 when you see SAM deployment.”

Real World

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“In production CI/CD pipelines, teams often automate this whole sequence using CodeBuild or CodePipeline, but the underlying build → package → deploy sequence always follows this order with an S3 bucket as the artifact store.”

(CTA) Stop Guessing, Start Mastering

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Disclaimer

This is a study note based on simulated scenarios for the AWS DVA-C02 exam.