Node.js scalability - handling the load
Is Node.js / Express scalable? How to grow Node.js app deployment to handle more traffic? Because Node.js is a single-threaded platform you might think most of the cores of your server will be sitting idle. Under the covers the Node.js implementation does use multiple threads, even though we only see one thread in our Node.js code. Instead it's pretty easy to set up multiple worker processes using any of several packages for that purpose.
Easily offload your CPU-intensive Node.js code with simple Express-based REST server: One way to deal with heavy computation code is to move it out to a back-end service. Express can easily be used to implement a REST service.