When building high-concurrency backend services, two ecosystems dominate the conversation: Node.js and Go (Golang). If you ask the internet how they handle concurrency, you’ll get the standard textbook answers: "Node.js is asynchronous and single-threaded, using an Event Loop." "Go is synchronous and multi-threaded, using lightweight Goroutines." But what do these statements actually mean under the hood? How do they look to your computer's CPU and RAM? To build bulletproof systems, we must stop