AWS Serverless

Quick Reference

Topic	Reference File	Key Insight
Lambda internals	`references/lambda-patterns.md`	Cold start happens per concurrent execution, not just once
Lambda Layers	`references/lambda-patterns.md`	Deployment optimization, NOT a package manager
Observability	`references/lambda-powertools.md`	Use Powertools for Logger, Tracer, Metrics — never print()
Monitoring/alarms	`references/monitoring.md`	Alert on symptoms (errors, latency), not causes (CPU)
Event-driven	`references/event-driven.md`	Single Lambda vs Step Functions decision; Standard/Express/Hybrid; Saga pattern
API Gateway	`references/api-gateway.md`	HTTP API ~70% cheaper; use REST API only for WAF/caching/usage plans