1. A method of automated text-based messaging interaction using natural language understanding technologies between a user and a self-service application platform, the method comprising the steps of: receiving, by the self-service application platform, a text-based message from the user; interpreting characters of the text-based message, by the self-service application platform, to determine words associated with the characters contained in the text-based message; using natural language understanding, by the self-service application platform, to determine an understanding of a content of the text-based message from the words; and selecting, by the self-service application platform, one or more grammars based on the understanding to formulate a text-based response message.