▸case-22 We are designing a PostgreSQL relational database schema on AWS RDS with 3NF normalization, composite B-tree indexes, and EXPLAIN ANALYZE query optimization for multi-table JOINs. What SQL DDL and indexing strategy should be used? | fail→fail | 29,082 | 23,570 | -19% | 1 | 1 | 0% | 5,669 | 12,983 | +129% | 0 | 0 | — |
▸case-01 We are configuring an AWS SQS queue as an event source for an AWS Lambda function with a 30-second execution timeout. The developer initially set the SQS queue visibility timeout to 30 seconds. What visibility timeout duration should be set on the queue, and how should retries be handled in AWS SAM? | pass→pass | 13,273 | 10,443 | -21% | 1 | 1 | 0% | 2,488 | 10,541 | +324% | 0 | 0 | — |
▸case-02 Our Node.js 20 Lambda function connects to a database pool. After executing the core handler code and returning the HTTP response, the Lambda invocation hangs until reaching its 30-second timeout instead of completing immediately. What property on the AWS Lambda context object must be set in the handler code to prevent this hanging behavior? | pass→pass | 3,487 | 5,169 | +48% | 1 | 1 | 0% | 627 | 9,457 | +1408% | 0 | 0 | — |
▸case-03 When processing a batch of 10 messages from an AWS SQS queue in AWS Lambda, one message fails due to bad payload syntax. We want Lambda to avoid failing the entire batch so that 9 valid messages are acknowledged. What configuration property is needed in the SAM event source, and what JSON structure should the handler return? | pass→pass | 7,207 | 5,829 | -19% | 1 | 1 | 0% | 1,282 | 9,688 | +656% | 0 | 0 | — |
▸case-04 A Node.js 20 Lambda function suffers from long cold start initialization because it imports the entire legacy AWS SDK v2 (`const AWS = require('aws-sdk')`). How should imports be structured in AWS SDK v3 to minimize bundle size and cold start latency when interacting with DynamoDB Document Client? | pass→pass | 13,953 | 11,464 | -18% | 1 | 1 | 0% | 2,266 | 10,789 | +376% | 0 | 0 | — |
▸case-05 An AWS Lambda function consumes a DynamoDB Stream with StreamViewType set to NEW_AND_OLD_IMAGES. The stream event records arrive formatted as raw DynamoDB AttributeValues (e.g. `{ 'id': { 'S': '123' } }`). What utility package and function from the AWS SDK v3 should be used to convert these into standard JavaScript objects? | pass→pass | 3,398 | 3,895 | +15% | 1 | 1 | 0% | 659 | 9,291 | +1310% | 0 | 0 | — |
▸case-06 We are running a Java 21 Lambda function deployed via AWS SAM that experiences 4-second cold starts on cold invocations. We want to reduce cold start initialization time using built-in Lambda capabilities without maintaining pre-warmed provisioned concurrency instances. What SAM template configuration property should be added to the function? | pass→pass | 5,352 | 5,071 | -5% | 1 | 1 | 0% | 1,003 | 9,383 | +835% | 0 | 0 | — |
▸case-07 We are designing a lightweight internal microservice on AWS that exposes basic HTTP REST endpoints backed by AWS Lambda. We need to choose between API Gateway HTTP API and API Gateway REST API. Which API type should be preferred for simple low-latency REST endpoints, and what is its expected latency advantage over REST API? | pass→pass | 9,162 | 6,514 | -29% | 1 | 1 | 0% | 1,546 | 9,630 | +523% | 0 | 0 | — |
▸case-08 Clients uploading 25MB file attachments directly through an AWS API Gateway endpoint are receiving HTTP 413 errors due to payload size limits. How should the backend architecture and AWS SDK v3 calls be redesigned to allow clients to upload large files safely to S3? | pass→pass | 15,438 | 19,874 | +29% | 1 | 1 | 0% | 3,145 | 12,566 | +300% | 0 | 0 | — |
▸case-23 A developer creates a SAM template for an AWS Lambda function that makes multiple HTTP requests to external payment processing APIs, but sets `Timeout: 2`. Why is a 2-second timeout configuration problematic, and how should it be adjusted? | fail→pass | 13,137 | 14,027 | +7% | 1 | 1 | 0% | 2,142 | 10,839 | +406% | 0 | 0 | — |
▸case-09 An AWS S3-triggered Lambda function processes newly uploaded files and inadvertently writes transformed output files back into the same S3 bucket root, causing an infinite execution loop and surging costs. What Lambda concurrency configuration and S3 key design patterns should be implemented to stop and prevent this loop? | pass→pass | 12,655 | 11,665 | -8% | 1 | 1 | 0% | 2,217 | 10,620 | +379% | 0 | 0 | — |
▸case-10 An AWS Lambda function iterates through a large list of batch records, but occasionally runs past its 30-second timeout and terminates abruptly without saving progress. What method on the Lambda context object can be polled inside the loop to gracefully detect that execution time is running out? | pass→pass | 5,040 | 6,075 | +21% | 1 | 1 | 0% | 934 | 9,706 | +939% | 0 | 0 | — |
▸case-11 An AWS Lambda function running in a private VPC subnet needs to make frequent read requests to DynamoDB and S3. Traffic currently routes through a NAT Gateway, incurring high networking costs and latency. What AWS VPC infrastructure construct should be added to connect the Lambda function directly to S3 and DynamoDB without public internet routing? | pass→pass | 6,034 | 8,711 | +44% | 1 | 1 | 0% | 1,075 | 10,196 | +848% | 0 | 0 | — |
▸case-12 A Node.js Lambda function downloading a large JSON object from AWS S3 runs out of memory and crashes with an out-of-memory error. Loading the full object payload into memory exceeds the function's heap limit. How should the S3 object response body in AWS SDK v3 be processed to avoid loading the full file into memory at once? | pass→pass | 13,901 | 10,681 | -23% | 1 | 1 | 0% | 2,642 | 10,609 | +302% | 0 | 0 | — |
▸case-13 We are configuring an AWS Lambda function for CPU-intensive data processing. What memory allocation size (in MB) guarantees that the function receives one full vCPU core equivalent? | fail→fail | 5,812 | 6,757 | +16% | 1 | 1 | 0% | 1,015 | 9,694 | +855% | 0 | 0 | — |
▸case-14 Following recent AWS billing changes for Lambda, our CloudWatch costs show charges for function initialization during cold starts. What specific report identifier in CloudWatch Logs indicates the cold start initialization duration, and how does AWS now bill this phase? | fail→pass | 17,157 | 9,370 | -45% | 1 | 1 | 0% | 2,863 | 10,161 | +255% | 0 | 0 | — |
▸case-15 An AWS Lambda function handler contains hardcoded string references like `TableName: 'ProdOrdersTable'` inside its business logic code. How should table references be passed to the Lambda handler to ensure portability across staging and production environments? | pass→pass | 10,812 | 8,940 | -17% | 1 | 1 | 0% | 1,969 | 10,349 | +426% | 0 | 0 | — |
▸case-16 In a Python AWS Lambda function using boto3, client initialization (`boto3.resource('dynamodb')`) is currently written inside the `def handler(event, context):` function body. Where should the client initialization code be placed to optimize performance across warm function invocations? | pass→pass | 7,085 | 6,342 | -10% | 1 | 1 | 0% | 1,283 | 9,652 | +652% | 0 | 0 | — |
▸case-17 A developer working locally wants to test and debug an AWS SAM serverless application. What AWS SAM CLI command starts a local emulated API Gateway server, and what command invokes a single function locally with a test event file? | pass→pass | 3,200 | 3,263 | +2% | 1 | 1 | 0% | 548 | 9,093 | +1559% | 0 | 0 | — |
▸case-18 In an AWS CDK TypeScript stack, we have defined an `aws_dynamodb.Table` named `itemsTable` and an `aws_lambda.Function` named `getItemFn`. What CDK method should be called on `itemsTable` to grant read permissions to `getItemFn`, and what CDK class integrates the function with an API Gateway resource method? | pass→pass | 5,222 | 4,758 | -9% | 1 | 1 | 0% | 1,048 | 9,438 | +801% | 0 | 0 | — |
▸case-19 When optimizing an AWS Lambda application for cold start latency, a team is deciding between reducing package size, enabling SnapStart, increasing memory size, lazy loading imports, and purchasing Provisioned Concurrency. What priority order should be followed, and where does Provisioned Concurrency rank? | fail→pass | 16,100 | 9,812 | -39% | 1 | 1 | 0% | 2,504 | 10,144 | +305% | 0 | 0 | — |
▸case-20 We are deploying a containerized API service to Google Cloud Run using GCP gcloud CLI and SAM/CloudFormation templates. How do we configure auto-scaling max instances and container concurrency limits for Cloud Run? | fail→pass | 16,321 | 11,087 | -32% | 1 | 1 | 0% | 2,941 | 10,468 | +256% | 0 | 0 | — |
▸case-21 How do I configure an Azure Functions C# project with host.json and function.json settings for binding to an Azure Event Grid topic trigger? | fail→fail | 15,305 | 13,279 | -13% | 1 | 1 | 0% | 2,758 | 11,028 | +300% | 0 | 0 | — |
▸case-24 An asynchronous AWS Lambda function triggered by S3 file creation events currently has no failure destination configured. When an invocation fails repeatedly, the records are lost without trace. What infrastructure component should be added to capture failed asynchronous invocations? | fail→pass | 8,051 | 10,256 | +27% | 1 | 1 | 0% | 1,332 | 10,321 | +675% | 0 | 0 | — |