[nasalgoat]

Yes, and it works fine as long as you accept that data will need to be migrated at some point when you run out of memory and/or instances.

To put this off as long as possible, you can max out the memory in your boxes and use a large number of servers - 100s in some cases - running on those servers, hopefully with less than 1 per CPU core to maximize performance.

Then if you begin maxing out memory, you can easily split those servers onto their own hardware. My calculations showed that would allow scaling to trillions of keys without problems.