Comment by try-working

I recently wrote about first principles of model routing that I've learnt building a model router.

The model pool should be kept small, and models in the pool should be clearly differentiated. For example, one large frontier model for quality, one small, fast and cheap model like DeepSeek V4 Flash for routing work.

These two principles by themselves solve the issues with caching, with routing decision making. I routinely hit >99% cache while routing between GPT 5.4 and DeepSeek.

https://try.works/first-principles-of-model-routing