I feel I should point out that if you need performance and you're mostly only interested in classic PyTorch or TensorFlow style machine learning (i.e. you don't

I feel I should point out that if you need performance and you're mostly only interested in classic PyTorch or TensorFlow style machine learning (i.e. you don't need Flux.jl's characteristic flexibility), then you should really check out KNet.jl [1]. KNet is generally around the same flexibility and performance as something like PyTorch. It doesn't get nearly as much attention as Flux because it's less novel, but it really should be looked at more. [1] https://github.com/denizyuret/Knet.jl https://github.com/denizyuret/Knet.jl