Create a Dockerfile for a Python FastAPI application. The app uses the files in this directory, requires Python 3.9 or later, needs to install dependencies from requirements.txt, and should expose port 8000 for the FastAPI server. Save this configuration to the Dockerfile in my backend directory.

Create a Dockerfile for a React application built with Vite. The app should install dependencies, build the production version, and serve it using a web server like nginx on port 80. Save this configuration to the Dockerfile in my frontend directory.