Context An API endpoint receives video file uploads that are buffered entirely in memory before being saved, causing frequent OutOfMemory crashes on large files. The Problem The current implementation uses multer with memoryStorage, loading the full file into a Buffer before any processing. Constraints Stream the upload directly to Amazon S3 using the AWS SDK v3 Upload class. Use multer with a custom storage engine or pipe the raw request stream. Never buffer the entire file in memory. Expected Deliverable An Express endpoint streaming file uploads directly to S3 using piped streams, with no full in-memory buffering regardless of file size.