1. A system comprising: a computer-readable memory storing executable instructions; and one or more processors in communication with the computer-readable memory, wherein the one or more processors are programmed by the executable instructions to at least: receive text corresponding to at least a portion of a user input; generate a first natural language understanding (“NLU”) result using the text and a first NLU module, wherein the first NLU module is associated with a first subject matter, and wherein the first NLU result is associated with a first score indicative of a confidence in the first NLU result; generate a second NLU result using the text and a second NLU module, wherein the second NLU module is associated with a second subject matter, and wherein the second NLU result is associated with a second score indicative of a confidence in the second NLU result; select the first NLU result based at least partly on the first score and the second score; and generate a response based at least partly on the first NLU result.