What is the fastest way to experiment with Apollo Router/Federation?

I am not new to GraphQL but am entirely new to Apollo Federation. I have no GraphQL servers available to me right now as I changed companies but looking to learn about federation/router quickly and creating a PoC with two trivial backends. Tried DGraph for these two backends, as I only needed to feed the GraphQL SDL but ran into problems wit that: Cannot Use Apollo Federation with Multiple Dgraph Instances - GraphQL - Discuss Dgraph

Can anyone recommend a non-DGraph back-end (or solve that issue) for two trivial GraphQL services, one containing “Containers” and the other containing “Items”?

I need very little more than that. DGraph sounded perfect, until it wasn’t. Looking for minimal work here, to demo Federation/Router but with the types and context relevant to my audience. These will be (re)implemented fully and properly later.