Awesome to see the rising number of people interested in using Nim for Data Science.
Andrea has written a neural network (Perceptron to be exact) using linalg, Neo's predecessor: https://github.com/unicredit/neurotic.
I've also written my own Perceptron based on Karpathy's "Neural network for hackers": https://github.com/mratsim/nim-rmad/blob/master/examples/ex04_2_hidden_layers_neural_net.nim and I'm working hard to get a proper Nim tensor library up and running.