[whimsicalism]

> There are places where things like eigenvectors / eigenvalues or svd come into play, but those are pretty rare and not part of modern architectures (tbh, I still don't really have a good intuition for them)

This stuff is part of modern optimizers. You can often view a lot of optimizers as doing something similar to what is called mirror/'spectral descent.'

[tomrod]

Indeed. "Spectral" describes the collection of eigenvalues!