Single Node.js instances have throughput limits, and production applications require multiple instances for high availability and horizontal scaling. As the creator of CoreUI with over 12 years of Node.js experience since 2014, I’ve architected load-balanced systems serving millions of requests daily. Load balancing distributes incoming traffic across multiple Node.js processes or servers, improving performance and providing redundancy if instances fail. The most common approach uses Nginx as a reverse proxy to balance requests across multiple Node.js instances.

Node.js runs on a single thread by default, which means a single CPU-intensive task can block all requests and multi-core systems are underutilized. With over 12 years of Node.js development experience since 2014 and as the creator of CoreUI, I’ve scaled numerous APIs to handle thousands of concurrent requests. The cluster module allows you to spawn multiple worker processes that share the same server port, distributing load across all CPU cores. This approach dramatically improves throughput and provides automatic restart capability when workers crash.