Node.js is frequently criticized for performance issues, often linked to memory management, and understanding its inner workings is crucial to avoiding these pitfalls. Unlike short-lived processes like PHP, Node.js applications are long-running, which provides benefits such as reusable database connections but also potential memory-related challenges. Node.js uses the V8 JavaScript engine to manage memory, employing a garbage collection mechanism to allocate and free memory. However, improperly managed memory can lead to leaks, affecting application performance. The article explores how V8 divides memory into segments and utilizes Scavenge and Mark-Sweep garbage collection methods, and how memory usage can be monitored using Node.js's process.memoryUsage() function. It discusses memory leaks, illustrating how they can occur through retained references and how tools like Chrome developer tools and V8-profiler can be used to analyze memory usage patterns and pinpoint leaks. Solutions for preventing and fixing memory leaks are also presented, emphasizing the importance of setting variables to null to break reference chains. Additionally, Dynatrace is suggested as a tool for broader application monitoring and insight, with a Node.js agent available for comprehensive analysis. The post is part of the author's research on enhancing Node.js instrumentation, with some tools already integrated into their product.