Federated Learning (FL) is a distributed machine learning (ML) paradigm that
enables multiple parties to jointly re-train a shared model without sharing
their data with any other parties, offering advantages in both scale and
privacy. We propose a framework to augment this collaborative model-building
with per-user domain adaptation. We show that this technique improves model
accuracy for all users, using both real and synthetic data, and that this
improvement is much more pronounced when differential privacy bounds are
imposed on the FL model.