Is Node.js Single-Threaded... or Not?
You’ve probably heard: “Node.js is single-threaded.” That statement is only partially correct. The JavaScript engine (V8) is single-threaded. Node.js as a runtime is not. Under the hood, Node.js uses multiple threads — through libuv and the operating system — to handle I/O and computationally expensive work. So the real question isn’t whether Node.js is single-threaded. It’s.