Part 4: Decoupled Architecture

Lab: Serverless “Web + Worker” File Pipeline (API Gateway + Lambda + S3) Goal build a serverless architecture where: Client calls API Gateway endpoint: POST /presign Web Lambda returns a presigned S3 PUT URL Client uploads a file to S3 using the presigned URL into uploads/ Worker Lambda automatically moves the file to processed/ Architecture Client → API Gateway (HTTP API) → Web Lambda (presign) → S3 (uploads/) S3 event → Worker Lambda → S3 (processed/) Part 0 — Prerequisites AWS account AWS CLI configured ( aws configure ) on Mac Python 3 available ( python3 --version ) Region: yours Check your AWS account identity: aws sts get-caller-identity Part 1 — Create S3 Bucket + Folders Create bucket (console): S3 → Create bucket Name: student-upload-bucket-<initials> (example: student-upload-bucket-aj ) Region: us-east-2 Keep defaults Create prefixes (folders): In bucket, create folder: uploads/ Create folder: processed/ Part 2 — Create Web Lambda (Presign URL Generator) 2.1 Create IAM Role