What are the methods for deploying Flask applications to server environments for running in production mode?

For deploying Flask applications in production, WSGI servers are typically used, which ensure stable and efficient operation of the application. Main methods:

• Gunicorn — a popular WSGI HTTP server for UNIX. It runs the Flask application and handles requests.
• uWSGI — a powerful server with many configurations, often used together with Nginx.
• Nginx — as a reverse proxy server that receives requests and forwards them to the WSGI server.

A typical scheme: Nginx receives HTTP requests, proxies them to Gunicorn/uWSGI, which runs the Flask application.

Example of launching with Gunicorn:

gunicorn -w 4 -b 0.0.0.0:8000 myapp:app

where -w 4 is the number of workers, myapp:app is the module and Flask application object.

You can also use containerization (Docker) and orchestration (Kubernetes) for scalable deployment.

For simple cases, the built-in Flask server can be used, but it is not intended for production.