AWS architecture blueprint for an API Gateway to SQS pattern

Blueprint Requirements:
Architecture Components:

- API Gateway Layer:
Set up an Amazon API Gateway (HTTP API) endpoint to receive incoming HTTP requests.
Configure throttling limits to control API access and prevent overloads.
Variables:
    {{PROJECT_NAME}}: The base name of the project.
    {{STAGE}}: Environment stage (e.g., dev, prod).
    {{API_THROTTLING}}: Number of requests per second to control rate limits.


- Queue Layer:
Create an SQS queue to hold messages from API requests for asynchronous processing.
Configure the queue to use a dead-letter queue (DLQ) for handling unprocessed messages after exceeding retry limits.
Variables:
    {{QUEUE_RETENTION}}: The retention period (in days) for messages in the queue.
    {{BATCH_SIZE}}: The number of messages to process per batch in Lambda.
    {{DLQ_RETRIES}}: Maximum retry attempts for failed messages before moving to DLQ.
    Resource Naming:
        Queue: Named as {{PROJECT_NAME}}-{{STAGE}}-queue.
        DLQ: Named as {{PROJECT_NAME}}-{{STAGE}}-dlq.

- Processing Layer:
Create a Lambda function to consume messages from the SQS queue and process them.
Configure the Lambda function’s concurrency and batch size to optimize message handling.
Variables:
    {{BATCH_SIZE}}: Number of messages processed in a single batch.
    {{DLQ_RETRIES}}: Number of retry attempts for each message before moving it to the DLQ.

- Error Handling and DLQ:
Use a Dead Letter Queue (DLQ) attached to the primary SQS queue for managing failed message processing.
Set up retry logic for handling transient errors and automatic redirection to the DLQ if retries are exhausted.
Variables:
    {{DLQ_RETRIES}}: Configurable retry limit for messages before moving to DLQ.

- Configuration Options:
Resource Naming Conventions:
    Stack Name: {{PROJECT_NAME}}-{{STAGE}}-queue-stack
    Resource Names:
        Queue: {{PROJECT_NAME}}-{{STAGE}}-queue
        DLQ: {{PROJECT_NAME}}-{{STAGE}}-dlq
        API Gateway: {{PROJECT_NAME}}-{{STAGE}}-http-api

Configuration Parameters:
    QueueRetention: {{QUEUE_RETENTION}} days
    BatchSize: {{BATCH_SIZE}}
    MaxRetries: {{DLQ_RETRIES}}
    Throttling: {{API_THROTTLING}} requests per second

- Extendability and Customization:

Security and Compliance:
Use IAM roles with least privilege for API Gateway, Lambda, and SQS.
Add KMS encryption for both SQS and DLQ for data security.
Enable VPC support if needed for Lambda and other network resources for enhanced isolation and compliance requirements.

Monitoring and Observability:
Include CloudWatch logging and metrics for monitoring API requests, queue depth, and Lambda execution.
Provide hooks to integrate custom observability tools for detailed tracing and monitoring requirements.

- Documentation:
README:
Include a comprehensive README file with instructions for setting up the CDK environment, configuring each component, and usage examples for deploying the stack.

- Purpose:
This CDK-based blueprint provides a flexible foundation for implementing an asynchronous API-driven processing pattern on AWS, allowing for future scaling, custom processing logic, and integration with additional services as requirements evolve.