This pattern deploys an AWS Lambda function that streams a file from a URL and stores it in Amazon S3 using multipart upload.

The file is downloaded in configurable chunks (default 512 MB, clamped between 5 MB and 5 GB) and written to /tmp before being uploaded as individual parts. Each chunk is cleaned up from /tmp after upload, allowing the function to handle files larger than Lambda's memory or ephemeral storage limits.

SHA256 checksums are calculated for each part and verified on completion. If any step fails, the multipart upload is automatically aborted to avoid orphaned parts.