[KirinDave]

> You don't really need a graph to support different backends. One popular approach is to have different array implementations (e.g. CPU and GPU arrays).

And now you can (waves arms) write it twice! Alternatively, you can make the interfaces between various impls be exactly the same but rename them so they're purpose-named. Then you've written Graph, for the most part.

[candiodari]

Except your graph is symbolic, and good luck getting a breakpoint to fire when the calculation is happening ... Or if you don't like debugging, the problem manifests itself with merely printing values too.