Lambda Just Got a File System. I Put AI Agents on It.

You've written this code before. An S3 event fires, your Lambda function wakes up, and the first thing it does is download a file to /tmp. Process it. Upload the result. Clean up /tmp so you don't run out of space. Repeat for every file, every invocation, every function in your pipeline. S3 Files changes that. You mount your S3 bucket as a local file system, and your Lambda code just uses open. I built a set of AI code review agents that share a workspace through a mounted S3 bucket, orchestrated by a durable function, and the file access code is the most boring part of the whole project.