Flows interacting with S3 events

Hi all,
tl:dr -
I’m trying to interact effectively with an event driven architecture inside my main flow.

I’m trying to write a main flow that depends on 10 files (with known paths) that exist in an s3 bucket.

If the files already exist my main flow starts some subflow for each of them and than merges all the responses so that’s no problem.

My issue is: what if my main flow is called before all the files exist?
I see that the simplest way to interact with s3 is basically polling, which isn’t great for me. also, I would love to start each subflow as soon as the relevant s3 file is created.
Is there a way for a flow to subscribe to specific s3 events and trigger subflows with those events?