Now, today, under the hood, Sprites are still Fly Machines. The Sprite storage stack is organized around the JuiceFS model (in fact, we currently use a very hacked-up JuiceFS, with a rewritten SQLite metadata backend). Our preference for object storage goes further than the Sprite storage stack. The global orchestrator for Sprites is an Elixir/Phoenix app that uses object storage as the primary source of metadata for accounts. Sprites live alongside Fly Machines in our architecture.