There has never been an S3 limit. Some of our customers have millions of objects in a single bucket. When you do something like this you need to make sure that

There has never been an S3 limit. Some of our customers have millions of objects in a single bucket. When you do something like this you need to make sure that you have a good distribution of keys across the name space, and you need to think twice before you decide to write code to list the entire bucket. In most use cases at this scale, metadata and indexing are handled by something other than S3.