titleRouteProfile: Elucidating the Design Space of LLM Profiles for Routing
authorsJingjun Xu, Hongji Pu, Tao Feng, Haozhen Zhang, Jiaxuan You, Ge Liu
date2026-04-30
venuearXiv (preprint, not peer reviewed)
idarXiv:2605.00180
affiliationUniversity of Illinois at Urbana-Champaign
upvotes29 (Hugging Face Daily Papers, 2026-11-01)
linksabs pdf hf code
abstractAs the large language model (LLM) ecosystem expands, individual models exhibit varying capabilities across queries, benchmarks, and domains, motivating the development of LLM routing. While prior work has largely focused on router mechanism design, LLM profiles, which capture model capabilities, remain underexplored. In this work, we ask: How does LLM profile design affect routing performance across different routers? Addressing this question helps clarify the role of profiles in routing, disentangle profile design from router design, and enable fairer comparison and more principled development of routing systems. To this end, we view LLM profiling as a structured information integration problem over heterogeneous interaction histories. We develop a general design space of LLM profiles, named RouteProfile, along four key dimensions: organizational form, representation type, aggregation depth, and learning configuration. Through systematic evaluation across three representative routers under both standard and new-LLM generalization settings, we show that: (1) structured profiles consistently outperform flat ones; (2) query-level signals are more reliable than coarse domain-level signals; and (3) generalization to newly introduced models benefits most from structured profiles under trainable configurations. Overall, our work highlights LLM profile design as an important direction for future routing research.

cite

@misc{xu2026routeprofile,
  title={RouteProfile: Elucidating the Design Space of LLM Profiles for Routing},
  author={Jingjun Xu and Hongji Pu and Tao Feng and Haozhen Zhang and Jiaxuan You and Ge Liu},
  year={2026},
  eprint={2605.00180},
  archivePrefix={arXiv},
  url={https://arxiv.org/abs/2605.00180}
}