Explore how to build AI-powered applications using FastAPI and JavaScript with OpenAI's GPT-3.5-turbo and GPT-4 APIs in this 22-minute tutorial video. Learn about challenging concepts such as CORS Middleware, static files, routes, and GET/POST methods. Dive into code reviews for both simple and complex examples, understand the importance of static folders and CORS Middleware, and compare GET vs POST methods. Gain practical insights into web app development using FastAPI, HTML, Tailwind CSS, and JavaScript while leveraging OpenAI's powerful language models.