#functions

Build serverless with AWS Lambda. Architecture: 1. Function handler receives event. 2. Stateless execution. 3. Cold start optimization. 4. Environment variables for config. 5. IAM roles for permissions. 6. API Gateway for HTTP triggers. 7. EventBridge for scheduling. 8. CloudWatch for logs and monitoring. Use Serverless Framework or SAM. Keep functions small and focused. Mind execution time limits.