A system can include one or more processors; memory; a data interface that receives data; a control interface that transmits control signals for control of pumps of a hydraulic fracturing operation; and one or more components that can include one or more of a modeling component that predicts pressure in a well fluidly coupled to at least one of the pumps, a pumping rate adjustment component that generates a pumping rate control signal for transmission via the control interface, a capacity component that estimates a real-time pumping capacity for each individual pump, and a control component that, for a target pumping rate for the pumps during the hydraulic fracturing operation, generates at least one of engine throttle and transmission gear settings for each of the individual pumps using an estimated real-time pumping capacity for each individual pump where the settings are transmissible via the control interface.