# Expert Specialization Probe: Token Routing Statistics + Language/Domain Specialization

> Source: https://sukruyusufkaya.com/en/learn/fine-tuning-cookbook/ftc-expert-specialization-probe
> Updated: 2026-05-14T14:42:53.642Z
> Category: Fine-Tuning Cookbook (Model-by-Model)
> Module: Part V — MoE Internals & Fine-Tuning
**TLDR:** MoE's secret: some experts 'specialize' in math, code, Turkish, formal writing. Probe to measure specialization: feed domain-specific test prompts (math, code, TR-chat), quantify which experts activate. TR specialization map of Mixtral 8×7B.