Portrait
Ghibli me at Tianchi, Xinjiang.
Rixin (Ryan) Liu
Portrait
Ghibli me at Tianchi, Xinjiang.

Hey, I'm Rixin, but you can call me Ryan. I'm a first-year CS PhD student at Rice University advised by Prof. Jiarong Xing. Prior to this, I got my B.E. in Computer Science and Technology from South China University of Technology in 2025.

About my research, overall, I’m a system researcher. My earlier work focused on high-performance networking, particularly on RDMA, programmable switches, and DPUs. Currently, my research centers on MLSys, aiming to address system and algorithmic challenges in a future dominated by specialized language models. My recent work primarily involves GPUs and LLM routing.

I’m always happy to connect and discuss possible collaborations. Please don’t hesitate to contact me if you’re interested in related topics.


Education
  • Rice University
    Rice University
    Department of Computer Science
    Ph.D. Student
    Sep. 2025 - present
  • South China University of Technology
    South China University of Technology
    B.E. in Computer Science and Technology
    Sep. 2021 - Jun. 2025
Honors & Awards
  • Recipient of the "Vibe Coding Excellence Award"
    2025
  • Awarded "Best Use of Ctrl-C Ctrl-V"
    2025
  • Recipient of the “Accidentally Fixed the Bug” Honor
    2025
News
2025
Our paper got into the NeurIPS 2025 Workshop on LLM Evaluation — it points out three main problems with current LLM Router benchmarks. Read more
Sep 23
I started my first year as a CS Phd student at Rice University!
Aug 18
Selected Publications (view all )
RouterArena: An Open Platform for Comprehensive Comparison of LLM Routers
RouterArena: An Open Platform for Comprehensive Comparison of LLM Routers

Yifan Lu*, Rixin Liu*, Jiayi Yuan*, Xingqi Cui, Shenrun Zhang, Hongyi Liu, Jiarong Xing (* equal contribution)

Under review. 2025

Today's LLM ecosystem comprises a wide spectrum of models that differ in size, capability, and cost. No single model is optimal for all scenarios; hence, LLM routers have become essential for selecting the most appropriate model under varying circumstances. However, the rapid emergence of various routers makes choosing the right one increasingly challenging. To address this problem, we need a comprehensive router comparison and a standardized leaderboard, similar to those available for models. In this work, we introduce RouterArena, the first open platform enabling comprehensive comparison of LLM routers. RouterArena has (1) a principally constructed dataset with broad knowledge domain coverage, (2) distinguishable difficulty levels for each domain, (3) an extensive list of evaluation metrics, and (4) an automated framework for leaderboard updates. Leveraging our framework, we have produced the initial leaderboard with detailed metrics comparison as shown in Figure 1. We will make our platform open to the public soon.

RouterArena: An Open Platform for Comprehensive Comparison of LLM Routers

Yifan Lu*, Rixin Liu*, Jiayi Yuan*, Xingqi Cui, Shenrun Zhang, Hongyi Liu, Jiarong Xing (* equal contribution)

Under review. 2025

Today's LLM ecosystem comprises a wide spectrum of models that differ in size, capability, and cost. No single model is optimal for all scenarios; hence, LLM routers have become essential for selecting the most appropriate model under varying circumstances. However, the rapid emergence of various routers makes choosing the right one increasingly challenging. To address this problem, we need a comprehensive router comparison and a standardized leaderboard, similar to those available for models. In this work, we introduce RouterArena, the first open platform enabling comprehensive comparison of LLM routers. RouterArena has (1) a principally constructed dataset with broad knowledge domain coverage, (2) distinguishable difficulty levels for each domain, (3) an extensive list of evaluation metrics, and (4) an automated framework for leaderboard updates. Leveraging our framework, we have produced the initial leaderboard with detailed metrics comparison as shown in Figure 1. We will make our platform open to the public soon.

Who Routes the Router: Rethinking the Evaluation of LLM Routing Systems
Who Routes the Router: Rethinking the Evaluation of LLM Routing Systems

Jiayi Yuan*, Yifan Lu*, Rixin Liu*, Yu-Neng Chuang, Hongyi Liu, SHaochen Zhong, Yang Sui, Guanchu Wang, Jiarong Xing, Xia Hu (* equal contribution)

NeurIPS 2025 Workshop LLM Evaluation. 2025

The proliferation of Large Language Models (LLMs), each with different capabilities and costs, has driven the need for LLM routers that intelligently and dynamically select the best model for a given query. Evaluating these routing systems is important yet inherently challenging due to the complex interplay of multiple factors: the selection of representative input queries, the composition of the model pool, and the definition of comprehensive evaluation metrics for optimal routing decisions. Through extensive analysis of existing benchmarks, we identify critical limitations that may lead to incomplete results and/or misleading conclusions about router performance: (1) limited task diversity, (2) imbalanced model pools, and (3) oversimplified evaluation methodologies. To address these limitations, we propose a novel evaluation framework that incorporates diverse task distributions, a balanced model pool with complementary model strengths, and multi-faceted metrics that reflect real-world deployment scenarios. We implement this framework as an open-source benchmark, the code and dataset are shared anonymously

Who Routes the Router: Rethinking the Evaluation of LLM Routing Systems

Jiayi Yuan*, Yifan Lu*, Rixin Liu*, Yu-Neng Chuang, Hongyi Liu, SHaochen Zhong, Yang Sui, Guanchu Wang, Jiarong Xing, Xia Hu (* equal contribution)

NeurIPS 2025 Workshop LLM Evaluation. 2025

The proliferation of Large Language Models (LLMs), each with different capabilities and costs, has driven the need for LLM routers that intelligently and dynamically select the best model for a given query. Evaluating these routing systems is important yet inherently challenging due to the complex interplay of multiple factors: the selection of representative input queries, the composition of the model pool, and the definition of comprehensive evaluation metrics for optimal routing decisions. Through extensive analysis of existing benchmarks, we identify critical limitations that may lead to incomplete results and/or misleading conclusions about router performance: (1) limited task diversity, (2) imbalanced model pools, and (3) oversimplified evaluation methodologies. To address these limitations, we propose a novel evaluation framework that incorporates diverse task distributions, a balanced model pool with complementary model strengths, and multi-faceted metrics that reflect real-world deployment scenarios. We implement this framework as an open-source benchmark, the code and dataset are shared anonymously

All publications