Building an AI-powered WhatsApp chatbot to learn German using GPT-3, Twilio, and Node.js involves several steps. First, one needs to set up a Twilio account, obtain an OpenAI API key for the GPT-3 model, and create a Node.js application with the necessary dependencies. The chatbot is built by creating a webhook in the Twilio console that receives incoming messages and passes them on to the complete function, which communicates with the GPT-3 engine. The complete function generates responses using the GPT-3 model, and these responses are sent back to the user through TwiML. The chatbot can be tested by sending messages from a phone or computer, and it allows for endless possibilities such as generating dragon ball fan fiction or controlling a spooky ghost writer for Halloween.