Abstract: Embodiments are directed toward an artificial neural network (ANN) partitioned into a substantially invariant portion and a variant portion. In embodiments, the substantially invariant portion includes a plurality of programmable heterogeneous heterostructures disposed in an optical substrate, programmed at least in part by their arrangement in the optical substrate to combine and scatter input optical data to provide output optical data for the substantially invariant portion of the ANN. A photonic pathway includes the substantially invariant portion and is coupleable to provide output optical data to a variant portion of the ANN and the variant portion is to perform training of the ANN based at least in part on the provided output optical data. Other embodiments may be described and/or claimed.