Looks interesting. It is a bit hard to read and immediately make sense of. Maybe this comes with practice.

I think it's important not to load up on too many esoteric tricks or the code base becomes expensive to maintain (time/money).

I'm more inclined to build a small toolkit for common transforms like this at the point of usage.

Why not the entire JS inside GraphQL queries?

Now seriously, is this running in the client or in the server?

In theory, it can be used both on the client and server but we recommend using it on the client. Check out corresponding README section: https://github.com/APIs-guru/graphql-lodash#caching-clients

This seems really cool, is anyone here using it?

It has been just released, so probably there are not lots of users :) Share your feedback if you decide to use it