It depends on a few factors. The list objects call hides deleted and noncurrent versions, but it has to skip over them. Grouping prefixes also takes time, if th

It depends on a few factors. The list objects call hides deleted and noncurrent versions, but it has to skip over them. Grouping prefixes also takes time, if they contain a lot of noncurrent or deleted keys. A pathological case would be a prefix with 100 million deleted keys, and 1 actual key at the end. Listing the parent prefix takes a long time in this case - I’ve seen it take several minutes. If your bucket is pretty “normal” and doesn’t have this, or isn’t versioned, then you can do 4-5 thousand list requests a second, at any given key/prefix, in constant time. Or or you can explicitly list object versions (and not skip deleted keys) also in constant time. It all depends on your data: if you need to list all objects then yeah it’s gonna be slow because you need to paginate through all the objects. But the point is that you don’t have to do that if you don’t want to, unlike a traditional filesystem with a directory hierarchy. And this enables parallelisation: why list everything sequentially, when you can group the prefixes by some character (i.e “-“), then process each of those prefixes in parallel. The world is your oyster.