From 50K RPS to 5M RPS: The Hard-Won Insights That Only Come From Scale My Load Balancer Handles 5M RPS: Architecture and Lessons Learned From 50K RPS to 5M RPS: The Hard-Won Insights That Only Come From Scale Scaling load balancing to 5 million requests per second requires rethinking every assumption about network processing, memory management, and system architecture. So I remember this moment, right? We’re in a perf review meeting, staring at Black Friday: 50K RPS and I’m… calm. CPU ~15%, memory flat, p95 sane. Headroom for days — or so I said, smugly, into a room that would later haunt me. We celebrated that dashboard like it meant we were safe for a year. It didn’t. Two years and a few gray hairs later we’re at 5M RPS and the thing I believed most — “just add more boxes” — turned out to be the first lie scale tells you. At 50K you adjust knobs; at 5M you renegotiate physics. Every nanosecond becomes a character in the story.…