Old Zhang's AI Learning

May 30, 2026 · Artificial Intelligence

vLLM Semantic Router Deep Dive: Engineering Multimodal Routing and Bug Fixes

The article details the vLLM Semantic Router's Signal-Decision architecture, explores multimodal routing challenges, uncovers an 82% visual signal reversal issue, and walks through three layered bug fixes that restore cosine similarity above 0.999 across extensive tests.