This is a more advanced optimization and may require restructuring your application. Flask itself does not directly support asynchronous processing, so you might need to integrate with a background task manager like Celery, or use asynchronous frameworks like Quart.
Ensure that your static files (CSS, JavaScript) are already minified and served from a Content Delivery Network (CDN) or a separate optimized server. This reduces the load on your application server and ensures faster delivery of assets to users.