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.