A complex system that works is invariably found to have evolved from a simple system that worked. A complex system designed from scratch never works and cannot be patched up to make it work. You have to start over with a working simple system.

John Gall

(Almost) Differentiable Indexing of Tensors

Indexing tensors is at the core of numeros ML applications. In this post, I describe a strategy to index a tensor when we need to compute the gradient with respect to the index.