Ok so looking into this a bit more, that's exactly what they're doing. In fact, TensorFlow is linked as an example on the wiki page for automatic differentiation [https://en.wikipedia.org/wiki/Automatic_differentiation]

"TensorFlow™ is an open source software library for numerical computation using data flow graphs. Nodes in the graph represent mathematical operations, while the graph edges represent the multidimensional data arrays (tensors) communicated between them." [https://www.tensorflow.org/]

In retrospect the name "Tensor Flow" makes a lot more sense now - I had only ever seen it in the context of machine learning, and assumed it was pretty specific to that domain.