aws-serverless-eda

Create an API Gateway REST or HTTP API backed by Lambda functions using CDK or SAM, with each function handling a single responsibility. The skill provides TypeScript examples for API-driven microservices, including DynamoDB integration, IAM least-privilege grants, and X-Ray tracing.

Use Step Functions for orchestration instead of chaining Lambda invocations directly. State machines provide visual workflows, built-in retries and error handling, execution history, and service integrations without code, making complex flows easier to debug and maintain.

Track processed message IDs in DynamoDB with a conditional write that fails on duplicates, and return partial batch failures so only failed records are retried. The skill includes complete idempotency handler examples with TTL-based cleanup of processed records.

SQS provides point-to-point queueing with consumer-controlled polling, SNS enables pub/sub fan-out to multiple subscribers, and EventBridge offers content-based event routing with schema registries and cross-account delivery. The skill's EDA patterns reference covers when to combine them, such as SNS-to-SQS fan-out.

Minimize deployment package size with tree-shaking and minification, initialize SDK clients outside the handler, and use provisioned concurrency for latency-sensitive paths. Java functions can use SnapStart for up to 10x faster cold starts, and Graviton2 ARM64 improves price-performance.

Use canary or linear deployment preferences for production Lambda updates to shift traffic gradually while CloudWatch alarms monitor errors and latency. CodeDeploy automatically rolls back if alarms trigger, and pre/post-traffic hooks validate the new version before full rollout.