This Fibonacci example is purposely inefficient to demonstrate an important consideration for your applications. What happens to the Node.js event loop when running long computations? To see the effect, open two browser windows, each opened to the Fibonacci page. In one, enter the number 55 or greater, and in the other, enter 10. Note that the second window freezes, and if you leave it running long enough, the answer will eventually pop up in both windows. What's happening is the Node.js event loop is blocked from processing events because the Fibonacci algorithm is running and does not ever yield to the event loop.
Since Node.js has a single execution thread, processing requests depend ...