Mixture of experts

Shared expert

An always-on expert that every token passes through, alongside whatever the router picks.

DeepSeek-style MoE adds one or more shared experts that process every token unconditionally, in parallel with the routed top-k experts. The shared expert captures common knowledge every token needs, freeing the routed experts to specialize harder - which measurably improves quality at the same compute. Most 2025-generation MoE models (DeepSeek, GLM, Qwen-MoE, Nemotron) include one.

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