Dataloader is a project from Facebook and allows removing pressure from the database: https://github.com/facebook/dataloader .
As per the README, it does not replace shared application level caches. It's meant to be used per request, and prevent multiple DB calls when one will do. See https://github.com/facebook/dataloader/blob/master/README.md.
Premature optimisation for now, but will come in handy when we are in need for performance improvements.
See https://github.com/withspectrum/spectrum/tree/alpha/api/loaders for a JS implementation.