Part 2: Node.js Internals - Event Loop, libuv and Buffers

Discover in depth how Node.js really works under the hood: the event loop, libuv, buffers, and memory management. This article debunks myths like 'single-threaded' and explains how Node's C++ engine and the libuv library handle thousands of concurrent requests without blocking the main JavaScript thread. We analyze the phases of the event loop, the role of microtasks (Promises and nextTick), the difference between I/O-bound and CPU-intensive work, and when to use Worker Threads or clustering with PM2 to scale. We also address the true location of buffers in native memory versus the V8 heap, generational garbage collection, and typical memory leaks. All from a practical and professional perspective, designed for developers who want to master the performance of their applications. At Q2BSTUDIO we apply this knowledge to build custom applications that are robust and scalable, integrating AI for businesses and cloud services aws and azure solutions. Our team also offers advanced cybersecurity and business intelligence services with Power BI, as well as process automation and development of AI agents. An essential article for understanding the inner workings of Node and making informed technical decisions in custom software projects.