1. A language understanding system, the language understanding system comprising: a trained language understanding server, the trained language understanding server comprising: at least one processor; and memory encoding computer executable instructions that, when executed by the at least one processor, perform a method comprising: receiving a natural language input from a client device; sending the natural language input to a plurality of feature extractors in response to receiving the natural language input; receiving potential features from the plurality of feature extractors after sending the natural language input to the plurality of feature extractors; evaluating the potential features to determine input features for the natural language input; determining a semantic meaning of the natural language input based on the input features; and sending a response to the client device that includes the semantic meaning of the natural language input.