S3 ListObjects calls are eventually consistent (i.e. list-after-put). EMRFS [1] and S3Guard [2] mitigate this for data processing use cases.

[1] - https://docs.aws.amazon.com/emr/latest/ManagementGuide/emr-f... [2] - https://blog.cloudera.com/introducing-s3guard-s3-consistency...