User File Management in an api endpoint

1

Hello, I’m trying to make a website where users can upload pdf files and an api will read the pdfs and respond with a json file of key information(using aws architecture because that is the most scalable/I am familiar with it). What I have found so far is this needs post the files to S3, but if i design it like that, how will the api ensure it gets all the correct files. Do i need to generate an new s3 per project per user? What design pattern should I be looking at?