File Upload Patterns Priority: P0 (FOUNDATIONAL) - Magic Bytes : NEVER trust header or file extension. - Tool : Use or to verify actual buffer signature. - Limits : Set strict (5MB) in Multer config to prevent DoS. Streaming (Scalability) - Memory Warning : Default Multer crashes servers with large files. - Pattern : Use Streaming for any file 10MB. - Library : (direct upload to bucket) or (raw stream processing). - Architecture : 1. Client requests Signed URL from API. 2. Client uploads directly to S3/GCS (Bypassing API server completely). 3. Pro Tip : Only approach to scale file uploads inf…