A chatbot is created using Java Spring Boot, Twilio WhatsApp API and MongoDB Atlas for storing data. The application allows users to send a message with an Amazon product link to track the price of that product. The chatbot uses JavaScript library JSOUP to scrape the HTML content of the product page and extract the product name, URL and initial price. If the product is already being tracked, it sends a response to the user indicating that the product is already being monitored. Otherwise, it adds the user's phone number to the database for future tracking and updates the database with the latest price information. The chatbot also uses Twilio's WhatsApp Messaging Service to send messages to users when the price of their tracked products drops.