Cloud Object Storage AWS S3 (Recommended Default) Setup (SDK v3) Upload Presigned Download Multipart Upload (large files) Python (boto3) Java (Spring) Bucket Policy Patterns Public read for assets CORS for direct uploads Anti-Patterns | Anti-Pattern | Fix | |--------------|-----| | Proxying large files through server | Use presigned URLs for direct client upload/download | | No Content-Type on upload | Always set ContentType to enable correct browser behavior | | Predictable file keys | Use UUIDs or hashed paths to prevent enumeration | | No lifecycle rules | Set expiration for temp uploads,…