LLM Routing: How to cut AI Infrastructure costs by 70% Without losing quality

Running everything on frontier models is an operational mistake. Here is the routing architecture that reduced cost per task from $8.20 to $2.44 in production GPT-5.5 costs 34x than DeepSeek V4-Pro. 95% of your queries do not need frontier. Routing (upfront decision) and cascading (confidence-based fallback) solve different problems. Production uses both. ESKOM.ai went from $8.20 to $2.44 per completed task. Same quality. 70% cost reduction. Every week someone tells me the same thing: "I tested an AI agent and it was useless.