pre-signed URLs also allow you to set conditions such as file size limit, type of file, file name etc to ensure malicious party isn't uploading a massive 1 TB f

pre-signed URLs also allow you to set conditions such as file size limit, type of file, file name etc to ensure malicious party isn't uploading a massive 1 TB file into your bucket which you serve as profile pics. However, while amazon S3 supports these "conditions", others like backblaze implementing S3 may or may not implement it. So beware.