The present disclosure is directed techniques for executing a task or service using a virtual agent. A method includes: defining a plurality of intents; conducting a first tier of machine learning analysis to compare a received input string with a first subset of training phrases associated with the plurality of intents to extract one or more parameters of the received input string; conducting a second tier of machine learning analysis to compare an output of the first tier of machine learning analysis with a second subset of training phrases associated with the plurality of intents, wherein the comparison is used to generate respective similarity scores indicating whether the received input string matches one or more of the second subset of training phrases; selecting an intent from among the plurality of intents based on the respective similarity scores; and executing an action associated with the selected intent.