A company needs to migrate an on-premises SFTP service (currently running on a Linux VM) to AWS. Uploaded files are made available to downstream applications via an NFS share. The migration must provide high availability and present external vendors with a stable set of static public IP addresses that the vendors can allow. The company already has an AWS Direct Connect link between its data center and its VPC. Which solution meets these requirements with the least operational overhead?

The correct solution leverages AWS Transfer Family for SFTP, which is a fully managed service, minimizing operational overhead. Configuring an internet-facing VPC endpoint for Transfer Family and assigning Elastic IP addresses to each subnet ensures stable, static public IPs for vendors, meeting a key requirement. Storing uploaded files in Amazon EFS provides a highly available, scalable, and durable shared file system across multiple Availability Zones, directly replacing the existing NFS share. Downstream applications can then easily mount the EFS endpoint. The second incorrect option is less robust because it doesn't explicitly mention assigning Elastic IP addresses to subnets for stable public IPs, which is crucial for vendor allow-listing. The third option, using AWS Application Migration Service to lift-and-shift the VM, increases operational overhead by requiring management of an EC2 instance and the SFTP server software. The fourth option incorrectly suggests using Amazon FSx for Lustre, which is optimized for high-performance computing workloads and not a direct, cost-effective replacement for a general-purpose NFS share like EFS.