python # app.py def app(environ, start_response): status = '200 OK' headers = [('Content-type', 'text/plain')] start_response(status, headers) return [b"Hello, world!"] # gunicorn.conf.py bind = "127.0.0.1:8000" workers = 4 # Terminal command to start Gunicorn $ gunicorn -c gunicorn.conf.py app:app