Create an SMS chatbot using C#, Amazon Lex, and Twilio SMS. The application will accept requests like buy, sell, show portfolio, etc. A free Twilio account, a Twilio Phone Number with SMS capability, a free AWS account, and .NET 6.0 SDK are required prerequisites. Amazon Lex is an artificial intelligence service that allows developers to create voice or text-based conversational interfaces. The application uses several AWS services: Lex, Lambda and DynamoDB. To follow along, you will need an IAM user setup in your development environment. The project overview includes a diagram of the application flow, where customer sends an SMS to customer service, which invokes Amazon Lex callback, identifies user's intent and calls corresponding Lambda function, executes application logic, gets customer info from DynamoDB database, and prepares response. The chatbot has four intents: CheckStockPrice, GetPortfolio, BuyStocks, and SellStocks, each with its own processor class that implements the Process method to handle the intent. The Lambda function ties everything together by invoking the correct processor based on the intent name specified in the LexV2Event object. Finally, the chatbot is connected to Twilio SMS integration and tested via SMS.