Phase 3 Exam: Building Applications

A development team is building a serverless API that receives JSON payloads from a mobile application, validates the input, and stores the data in a DynamoDB table. The team wants to minimize operational overhead and avoid managing any servers. Which combination of AWS services should the team use to build this API?

A Lambda function processes messages from an SQS queue. The function takes an average of 45 seconds to process each message. The operations team notices that some messages are being processed more than once. Which configuration change is most likely to resolve the duplicate processing?

A solutions architect is designing a containerized application that must run on AWS. The application consists of 15 microservices, each with different CPU and memory requirements. The team does not want to manage EC2 instances, patch operating systems, or handle cluster capacity planning. Which ECS launch type should the architect recommend?

A team is deploying a CloudFormation stack that creates a VPC, subnets, an RDS instance, and a Lambda function. The stack creation fails because the RDS instance cannot be created (the specified instance class is not available in the selected Availability Zone). What happens to the resources that were successfully created before the failure?

A company runs a web application on Amazon ECS with the Fargate launch type. The application experiences variable traffic throughout the day. During peak hours, the current number of tasks cannot handle the load, resulting in slow response times. Which TWO actions should the team take to handle traffic spikes automatically? (Select TWO.)Select multiple

A developer is writing a buildspec.yml file for AWS CodeBuild. The build must install Node.js 20, run linting and unit tests before the main build, compile the application, and then push a Docker image to Amazon ECR after the build completes. In which buildspec phase should the developer place the `docker push` command?

A solutions architect needs to deploy the same infrastructure (VPC, subnets, security groups, EC2 instances) across three AWS accounts: development, staging, and production. The infrastructure must be identical in structure but use different instance types and CIDR ranges per environment. Which CloudFormation feature allows the architect to use a single template for all three environments?

A team is deploying a mission-critical e-commerce application to production. The team wants a deployment strategy that allows them to test the new version with a small percentage of real production traffic before routing all users to it. If the new version shows elevated error rates, the deployment must roll back automatically. Which deployment strategy meets these requirements?

A developer is troubleshooting a Lambda function that processes S3 event notifications. The function is supposed to generate thumbnails when images are uploaded to an S3 bucket. The function works correctly when tested manually with a test event in the Lambda console, but it does not trigger when images are uploaded to the bucket. Which TWO areas should the developer investigate? (Select TWO.)Select multiple

A team manages infrastructure using CloudFormation. They need to update a production stack to change the instance type of an EC2 instance from `t3.medium` to `t3.large`. Before applying the change, the team wants to preview exactly which resources will be modified and whether any resources will be replaced. Which CloudFormation feature should the team use?

A company is building a microservices application. One service processes payment transactions and must handle exactly 50 requests per second with consistent sub-100ms latency. The service runs continuously and has predictable, steady traffic. Another service generates monthly reports and runs for 10 minutes once per month. Which compute strategy best fits both workloads?

A developer is creating a CloudFormation template that provisions a Lambda function and a DynamoDB table. The Lambda function needs the DynamoDB table name as an environment variable. Which CloudFormation intrinsic function should the developer use to reference the table name dynamically in the template?

A solutions architect is designing a CI/CD pipeline for a web application. The pipeline must pull code from GitHub, build and test the application, deploy to a staging environment, wait for manual approval, and then deploy to production. Which pipeline structure correctly implements this workflow in AWS CodePipeline?

A Lambda function is configured with 128 MB of memory and a 3-second timeout. The function processes API Gateway requests and queries a DynamoDB table. During peak traffic, users report intermittent timeout errors. CloudWatch Logs show that the function occasionally takes 4 to 5 seconds to complete, and the "Max Memory Used" metric shows 125 MB. Which TWO changes should the developer make to resolve the issue? (Select TWO.)Select multiple

A team is using AWS SAM to define a serverless application. The application consists of a Lambda function triggered by an API Gateway endpoint and a DynamoDB table. Which SAM resource type should the team use to define the Lambda function, and what is the advantage of using SAM over plain CloudFormation for this use case?

A company runs a containerized application on ECS with the Fargate launch type. The application consists of a web frontend and a backend API, each defined as a separate ECS service. The web frontend must be accessible from the internet, but the backend API must only accept traffic from the web frontend. Which networking configuration achieves this?

Place the following steps in the correct order for how AWS CodePipeline processes a code change from a developer's push to production deployment. 1. CodeDeploy deploys the build artifact to the production environment using the configured deployment strategy. 2. The source stage detects a new commit on the configured branch and downloads the source code as an artifact. 3. A manual approval action pauses the pipeline and sends an SNS notification to the reviewer. 4. CodeBuild compiles the code, runs tests, and produces a build artifact.

A developer is building a Lambda function that processes uploaded CSV files from S3. Each file contains 500,000 rows and takes approximately 8 minutes to process. The developer configures the Lambda function with the maximum timeout of 15 minutes. After deployment, the function works for small files but fails with a "Task timed out" error for large files. CloudWatch metrics show the function uses 2,800 MB of memory out of the 3,008 MB allocated. Which approach should the developer take to resolve this?

A team is managing a CloudFormation stack that includes an RDS database instance. The team needs to update the stack to change the database engine version, which requires replacing the RDS instance. The team wants to prevent accidental deletion of the database during stack updates. Which CloudFormation feature should the team use?

A company is migrating from manual deployments to CI/CD. The team currently deploys a Node.js application by SSHing into EC2 instances and running scripts manually. They want to automate this process using AWS CodeDeploy. Which file must the team add to their application source code to tell CodeDeploy where to copy files and which scripts to run during deployment?

A solutions architect is comparing AWS CloudFormation, AWS SAM, and AWS CDK for a new project. The project involves a complex application with 50+ resources, conditional logic for multi-environment deployments, and the development team is proficient in TypeScript. Which IaC tool is the best fit for this project, and why?

A Lambda function is triggered by an API Gateway REST API. The function connects to an RDS PostgreSQL database in a private subnet. After deploying the function, all API requests return a timeout error. The function's CloudWatch Logs show no invocation records. Which TWO configuration issues should the developer investigate? (Select TWO.)Select multiple

A team is building a Docker image for an ECS task. The Dockerfile installs build tools (gcc, make), compiles a C extension for a Python application, and then runs the application. The resulting image is 1.2 GB. The team wants to reduce the image size without removing the C extension. Which approach should the team use?

A company has a CodePipeline that deploys a Lambda function using CloudFormation. The pipeline has been working correctly, but after a recent code change, the deploy stage fails with the error: "UPDATE_ROLLBACK_COMPLETE." The developer checks the CloudFormation events and sees that the Lambda function's code package exceeds the 250 MB unzipped deployment package limit. Which approach should the developer take to resolve this while keeping the pipeline functional?

A company is designing a deployment architecture for a microservices application running on Amazon ECS. The application serves real-time financial data and cannot tolerate any downtime during deployments. The team also needs the ability to instantly roll back to the previous version if the new deployment causes errors. The team uses CodePipeline with CodeDeploy for deployments. Which deployment configuration and architecture should the team implement? (Select THREE.)Select multiple