I believe that’s not possible natively in S3.
What are the possible alternatives?
- Try proxying the upload to S3 using your backend server, here you may implement websockets on the server so that it communicates with the browser by emitting a "FileCreated" event every time an upload is successful.
- You may also try uploading the file directly to S3 from the browser then you can implement a lambda function that will be triggered for each successful file upload. This lambda function will then notify your backend server via an http request and it will then relay the event to the browser by emitting websockets events.
Here you do not require additional services