aws-serverless

AWS Serverless

Domain expertise for building serverless applications on AWS: Lambda, API Gateway, Step Functions, EventBridge, event source mappings, concurrency, cold starts, deployment, and troubleshooting.

Works best with the AWS MCP server — run CLI commands, query CloudWatch, validate configs directly. All guidance also works with standard AWS CLI access.

Specialized skills — check these first

These cover capabilities and procedures the general references below do not. Several are specialized features or step-by-step tested procedures you would otherwise miss. Route to the matching skill before falling back to the references.

Advanced Lambda compute (easy to overlook)

Use this skill	When the workload involves
aws-lambda-microvms	Strong tenant isolation, sandboxed/untrusted code execution (AI agent code sandboxes, REPLs, notebooks, CI runners), long-lived sessions, suspend/resume with preserved state, port-listening servers (gRPC, WebSocket, custom TCP), Firecracker microVMs, snapshot-resumable compute, up to 8-hour lifetimes
aws-lambda-durable-functions	Durable execution, checkpoint-and-replay, long-running multi-step workflows written as plain code (TS/Python/Java), automatic state persistence, saga pattern in code, human-in-the-loop callbacks, executions up to 1 year, context.step/context.wait/context.invoke, withDurableExecution, durable-execution-sdk
aws-lambda-managed-instances	Lambda Managed Instances (LMI), capacity providers, EC2-backed Lambda, steady high-volume traffic (50M+ req/mo) wanting Savings Plans / Reserved Instance pricing, PerExecutionEnvironmentMaxConcurrency, CapacityProviderConfig, multi-concurrent execution environments

Step-by-step task procedures (tested CLI SOPs)

Use this skill	For the task
connecting-lambda-to-api-gateway	Wire an existing Lambda to a new REST/HTTP API: proxy integration, permissions, CORS, throttling, access logging, deployment
connecting-lambda-to-dynamodb	Connect Lambda to DynamoDB: IAM execution role, read/write permissions, stream event source mapping
creating-api-gateway-stage	Create an API Gateway stage with CloudWatch logging, X-Ray tracing, throttling, WAF association, and authorization
deploying-custom-domain-rest-api	Deploy a Regional REST API with custom domain: ACM cert, Lambda backend, request authorizer, base path mapping, Route 53 DNS
debugging-lambda-timeouts	Systematically diagnose a timing-out Lambda: config, CloudWatch logs/metrics, VPC, cold starts, memory, downstream calls
processing-s3-uploads-with-step-functions	Deploy an event-driven workflow: S3 upload → EventBridge → Step Functions → Lambda (small files) or Fargate (large files), with VPC/ECR/ECS/IAM

Routing (general references in this skill)

User need	Read
Building a new serverless app — pattern selection	architecture.md
Lambda config, cold starts, SnapStart, memory, VPC, layers, Function URLs	lambda.md
Concurrency (reserved, provisioned, ESM controls)	concurrency.md
Event sources (SQS, DynamoDB Streams, SNS, Kinesis), filtering, batch failures	event-sources.md
Step Functions, EventBridge rules/pipes/scheduler	orchestration.md
API Gateway quotas, authorizers, WebSocket	api-gateway.md
SAM/CDK resource types and fast iteration	deployment.md
Production readiness, observability, anti-patterns	production.md
Debugging an error (exact string → cause → fix)	troubleshooting.md
Powertools handler template	powertools-handler.py

Note: Reference files contain specific runtime versions, quotas, and feature matrices that change. When precision matters (production, runtime choice, quotas), confirm against current AWS documentation. The references focus on values and gotchas that are easy to get wrong — not on basics.