How to handle multiple requests at the same time

Question

In my application, I need to process numerous client requests simultaneously. What are the best methods to manage multiple requests efficiently, especially when it comes to handling asynchronous tasks in a scalable way? Are there certain programming practices or frameworks that excel at managing concurrent requests, and what challenges should I anticipate?

Any guidance on handling concurrency in high-traffic applications would be useful, especially in languages like Node.js or Python.