1. A computer-implemented method comprising: receiving, by a speech recognition model training system and from a client device, a request to generate a new speech recognition model for the client device, wherein the request includes: (i) one or more features extracted from speech data by a feature extractor on the client device, and (ii) metadata regarding the speech recognition model to be generated; generating, by the speech recognition model training system and using the one or more features extracted from speech data by the feature extractor on the client device, the new speech recognition model according to the metadata; and transmitting, by the speech recognition model training system and to the client device, at least a portion of the new speech recognition model.