A developer wrote an application that uses an AWS Lambda function to asynchronously generate short videos based on requests from customers. This video generation can take up to 10 minutes. After the v

The Lambda /tmp folder is ephemeral and scoped to a single execution environment instance; it is limited to 10 GB, not accessible from a browser URL, and the data is lost when the execution environment is recycled.

Amazon EFS can persist files, but it is a network file system accessible only within a VPC; there is no native mechanism to generate a browser-accessible pre-signed URL for an EFS file.

Storing the generated video in Amazon S3 provides durable, persistent object storage that is completely independent of the Lambda execution environment. A pre-signed URL can be generated with an expiration time of 3 hours or more and pushed to the customer's browser, allowing direct and secure download access for the required duration.

Amazon CloudFront is a CDN that distributes content from an origin (such as S3); video files are not stored directly in CloudFront, and generating pre-signed URLs requires an S3 origin origin or CloudFront signed URLs with additional key pair configuration, adding unnecessary complexity.