A developer needs to build and deploy a serverless application that has an API that mobile clients will use. The API will use Amazon DynamoDB and Amazon OpenSearch Service (Amazon Elasticsearch Service) as data sources. Responses that are sent to the clients will contain aggregated data from both data sources.
The developer must minimize the number of API endpoints and must minimize the number of API calls that are required to retrieve the necessary data.
Which solution should the developer use to meet these requirements?

A. GraphQL API on AWS AppSync
B. REST API on Amazon API Gateway
C. GraphQL API on an Amazon EC2 instance
D. REST API on AWS Elastic Beanstalk

A company is building an application for stock trading. The application needs sub-millisecond latency for processing trade requests. The company uses Amazon DynamoDB to store all the trading data that is used to process each trading request.
A development team performs load testing on the application and finds that the data retrieval time is higher than expected. The development team needs a solution that reduces the data retrieval time with the least possible effort.
Which solution meets these requirements?

A. Add local secondary indexes (LSIs) for the trading data.
B. Store the trading data in Amazon S3, and use S3 Transfer Acceleration.
C. Add retries with exponential backoff for DynamoDB queries.
D. Use DynamoDB Accelerator (DAX) to cache the trading data.

A developer is adding a feature to a client-side application so that users can upload videos to an Amazon S3 bucket.
What is the MOST secure way to give the application the ability to write files to the S3 bucket?

A. Update the S3 bucket policy to allow public write access. Allow any user to upload videos by removing the need to handle user authentication within the client-side application.
B. Create a new IAM policy and a corresponding IAM user with permissions to write to the S3 bucket. Store the key and the secret for the user in the application code. Use the key to authenticate the video uploads.
C. Configure the API layer of the application to have a new endpoint that creates signed URLs that allow an object to be put into the S3 bucket. Generate a presigned URL through this API call in the client application. Upload the video by using the signed URL.
D. Generate a new IAM key and a corresponding secret by using the AWS account root user credentials. Store the key and the secret for the user in the application code. Use the key to authenticate the video uploads.

A developer is designing a serverless application with two AWS Lambda functions to process photos. One Lambda function stores objects in an Amazon S3 bucket and stores the associated metadata in an Amazon DynamoDB table. The other Lambda function fetches the objects from the S3 bucket by using the metadata from the DynamoDB table. Both Lambda functions use the same Python library to perform complex computations and are approaching the quota for the maximum size of zipped deployment packages.
What should the developer do to reduce the size of the Lambda deployment packages with the LEAST operational overhead?

A. Package each Python library in its own .zip file archive. Deploy each Lambda function with its own copy of the library.
B. Create a Lambda layer with the required Python library. Use the Lambda layer in both Lambda functions.
C. Combine the two Lambda functions into one Lambda function. Deploy the Lambda function as a single .zip file archive.
D. Download the Python library to an S3 bucket. Program the Lambda functions to reference the object URLs.

A developer has a legacy application that is hosted on-premises. Other applications hosted on AWS depend on the on-premises application for proper functioning. In case of any application errors, the developer wants to be able to use Amazon CloudWatch to monitor and troubleshoot all applications from one place.
How can the developer accomplish this?

A. Install an AWS SDK on the on-premises server to automatically send logs to CloudWatch.
B. Download the CloudWatch agent to the on-premises server. Configure the agent to use IAM user credentials with permissions for CloudWatch.
C. Upload log files from the on-premises server to Amazon S3 and have CloudWatch read the files.
D. Upload log files from the on-premises server to an Amazon EC2 instance and have the instance forward the logs to CloudWatch.

A developer has a stateful web server on-premises that is being migrated to AWS. The developer must have greater elasticity in the new design.
How should the developer re-factor the application to make it more elastic? (Choose two.)

A. Use pessimistic concurrency on Amazon DynamoDB.
B. Use Amazon CloudFront with an Auto Scaling group.
C. Use Amazon CloudFront with an AWS Web Application Firewall.
D. Store session state data in an Amazon DynamoDB table.
E. Use an ELB with an Auto Scaling group.

A developer manages an application that interacts with Amazon RDS. After observing slow performance with read queries, the developer implements Amazon ElastiCache to update the cache immediately following the primary database update.
What will be the result of this approach to caching?

A. Caching will increase the load on the database instance because the cache is updated for every database update.
B. Caching will slow performance of the read queries because the cache is updated when the cache cannot find the requested data.
C. The cache will become large and expensive because the infrequently requested data is also written to the cache.
D. Overhead will be added to the initial response time because the cache is updated only after a cache miss.

A developer must extend an existing application that is based on the AWS Serverless Application Model (AWS SAM). The developer has used the AWS SAM CLI to create the project. The project contains different AWS Lambda functions.
Which combination of commands must the developer use to redeploy the AWS SAM application? (Choose two.)

A. sam init
B. sam validate
C. sam build
D. sam deploy
E. sam publish

A developer needs to deploy an application running on AWS Fargate using Amazon ECS. The application has environment variables that must be passed to a container for the application to initialize.
How should the environment variables be passed to the container?

A. Define an array that includes the environment variables under the environment parameter within the service definition.
B. Define an array that includes the environment variables under the environment parameter within the task definition.
C. Define an array that includes the environment variables under the entryPoint parameter within the task definition.
D. Define an array that includes the environment variables under the entryPoint parameter within the service definition.

A developer is creating a serverless web application and maintains different branches of code. The developer wants to avoid updating the Amazon API Gateway target endpoint each time a new code push is performed.
What solution would allow the developer to perform a code push efficiently, without the need to update the API Gateway?

A. Associate different AWS Lambda functions to an API Gateway target endpoint.
B. Create different stages in API Gateway. then associate API Gateway with AWS Lambda.
C. Create aliases and versions in AWS Lambda.
D. Tag the AWS Lambda functions with different names.