The parity-violating electron scattering community has made tremendous progress over the last twenty five years in their ability to measure tiny asymmetries of order 100 parts per billion (ppb) with beam-related corrections and systematic errors of a few ppb. Future experiments are planned for about an order of magnitude smaller asymmetries and with higher rates in the detectors. These new experiments pose new challenges for the beam instrumentation and for the strategy for setting up the beam. In this contribution to PAVI14 I discuss several of these challenges and demands, with a focus on developments at Jefferson Lab.