Most engineering teams don't think about file transfer until an enterprise customer asks for it. Then suddenly it becomes a critical requirement.
A few years ago, I assumed APIs would be enough for most integrations. In reality, many enterprises still rely on secure file transfer for exchanging invoices, remittance advice, payment reports, customer data, and financial documents. For organizations operating in regulated environments, SFTP remains one of the most widely accepted integration mechanisms.
The challenge is that enterprise-grade file exchange introduces a completely different set of architectural concerns. It is not simply about moving files from one location to another. You need to think about security, auditability, reliability, scalability, tenant isolation, operational overhead, and cost.
This article walks through the design principles behind building an enterprise SFTP integration platform on AWS. The focus is on architecture and decision making rather than implementation details.
The Problem
