Achieving state-of-the-art performance with AI agents does not always require the single largest model. This post details how an intelligent routing layer between models like Kimi K3 (open) and Fable 5 (closed) can yield 93 percent accuracy on agentic tasks.
This approach was up to 50X more cost-effective on long agentic loops compared to using a single, more expensive model. It is a critical insight for optimizing LLM inference costs and latency in production.
The team ran ~1,000 real agent tasks (SWE, Terminal, Algorithmic) through this system. The key takeaway is to “not pick a model, route,” which fundamentally changes how one might design LLM-powered systems.
This shows that infrastructure and orchestration decisions are just as crucial as model quality for practical applied AI.







