I recently received my Ph.D. degree from University of Science and Technology of China (USTC) in 2026, under the advisory of Prof. Defu Lian in School of Computer Science and Technology. I will join ByteDance-Douyin as a researcher, focusing on Large Ranking Models and LLM4Rec. I got my B.S. degree from University of Science and Technology of China (USTC) in 2021.
My research interest includes large language models, data mining, information retrieval, especially on recommender system. Recently my major research direction is on the large ranking models and LLM-driven recommendation. I have published several papers at the top international AI conferences with total 1900+ google scholar citations .
🔥 News
- 2026.06: 🎉🎉 Our paper MixFormer for co-scaling up dense and sequence in industrial recommenders is accepted by KDD 2026.
- 2025.08: 🎉🎉 Our work WESE for coorperative weak and strong agents is accepted by SCIS.
- 2025.03: 🎉🎉 Our work InteRecAgent for interactive recommendation is accepted by TOIS.
- 2025.01: 🎉🎉 Our work HyperGate for multi-domain multi-task recommendation is accepted by WWW 2025, accept rate 22.42%.
- 2025.01: 🎉🎉 Our work ToolACE for enhancing tool-using ability of LLM is accepted by ICLR 2025.
📖 Educations
- 2021.09 - 2026.06, School of Computer Science and Technology, University of Science and Technology of China (USTC), Ph.D.
- 2017.08 - 2021.06, School of Computer Science and Technology, University of Science and Technology of China (USTC), Bachelor.
💼 Work Experience
- 2026.07 - Now, Bytedance-Douyin, Shanghai, China.
- Researcher in Recommendation Group-Ranking Team
- Dive into: Large Ranking Models, LLM4Rec
🏢 Internships
- 2025.07 - 2026.06, Bytedance-Douyin, Shanghai, China.
- Intern in Recommendation Group-Ranking Team
- Dive into: Large Ranking Models
- 2023.11 - 2025.03, Huawei Noah’s Ark Lab, Shenzhen, China.
- Intern in Recommendation and Search Group lead by Ruiming Tang
- Dive into: Multi-domain and Multi-task Recommendation, LLM Agents
- Mentor: Weiwen Liu
- 2022.10 - 2023.10, Microsoft Research Asia, Beijing, China.
- Intern in Social Computing Group lead by Xing Xie
- Dive into: Responsible Recommendation, Recommendation Agent
- Mentor: Jianxun Lian
📝 Publications

MixFormer: Co-Scaling Up Dense and Sequence in Industrial Recommenders
Xu Huang, Hao Zhang, Zhifang Fan, Yunwen Huang, Zhuoxing Wei, Zheng Chai, Jinan Ni, Yuchao Zheng, Qiwei Chen
- MixFormer is a unified Transformer architecture for recommender systems that jointly models sequential behaviors and feature interactions within a single backbone.
- It enables effective co-scaling of dense capacity and sequence length, with a user-item decoupling strategy for efficiency.
- Large-scale online A/B tests on Douyin and Douyin Lite show consistent improvements in user engagement metrics including active days and in-app usage duration.

HyperGate: Hierarchical Perceptive Gating Network for Multi-domain Multi-task Recommendation
Xu Huang*, Xiaolong Chen*, Yichao Wang, Weiwen Liu, Yang Yang, Xingmei Wang, Defu Lian and Ruiming Tang
Project
- A hierarchical gating network for multi-domain and multi-task recommendation.
- We propose a contrastive domain and task representation augumentation module to extract domain and task embeddings, and a hierarchical gating network to construct a domain- and task-perceptive parameter-sharing network from the bottom up.
- The paper will be public soon.

ToolACE: Winning the Points of LLM Function Calling
Weiwen Liu*, Xu Huang*, Xingshan Zeng*, Xinlong Hao, Shuai Yu, Dexun Li, Shuai Wang, Weinan Gan, et al.

WESE: Weak Exploration to Strong Exploitation for LLM Agents
Xu Huang, Weiwen Liu, Xiaolong Chen, Xingmei Wang, Defu Lian, Yasheng Wang, Ruiming Tang, Enhong Chen
- A novel prompt-based method for LLM agents, leveraging weaker agent for exploration and stronger agent for exploitation.

Understanding the planning of LLM agents: A survey
Xu Huang, Weiwen Liu, Xiaolong Chen, Xingmei Wang, Hao Wang, Defu Lian, Yasheng Wang, Ruiming Tang, Enhong Chen
- A survey about the planning ability of LLM agents.

A Data-Centric Multi-Objective Learning Framework for Responsible Recommendation Systems
Xu Huang, Jianxun Lian, Hao Wang, Defu Lian, Xing Xie
- A data-centric framework for multi-objective learning in recommendation systems.
- Code

Recommender AI Agent: Integrating Large Language Models for Interactive Recommendations
Xu Huang, Jianxun Lian, Yuxuan Lei, Jing Yao, Defu Lian, Xing Xie
- A framework to build an interactive recommendation agent with LLM
- Code

RecStudio: Towards a Highly-Modularized Recommender System
Defu Lian(mentor), Xu Huang, Xiaolong Chen, Jin Chen, Xingmei Wang, Yankai Wang, Haoran Jin, Rui Fan, Zheng Liu, Le Wu, Enhong Chen
- A modularized recommender system library RecStudio was developped and released to public
- Project homepage

Cooperative Retriever and Ranker in Deep Recommenders
Xu Huang, Defu Lian, Jin Chen, Zheng Liu, Xing Xie, Enhong Chen
- An adaptive hard negative sampler was introduced to enhance the ranker
- An sampling based KL divergence was proposed to enhance the retriever

RecExplainer: Aligning Large Language Models for Explaining Recommendation Models
Yuxuan Lei, Jianxun Lian, Jing Yao, Xu Huang, Defu Lian, Xing Xie
- A novel approach to leverage LLMs as surrogate models for explaining black-box recommender models.

Learning-Efficient Yet Generalizable Collaborative Filtering for Item Recommendation
Yuanhao Pu, Xiaolong Chen, Xu Huang, Jin Chen, Defu Lian, Enhong Chen
- This work proposes a new square loss RG2 for recommendation based on the approximation of the softmax loss with Taylor expansion.
- We have studied the theoretical properties of the proposed loss in terms of generalization and consistency.

RecAI: Leveraging Large Language Models for Next-GenerationRecommender Systems
Jianxun Lian, Yuxuan Lei, Xu Huang, Jing Yao, Wei Xu, Xing Xie
- A practical toolkit designed to augmentor even revolutionize recommender systems with the advanced capabilities of Large Language Models.
- Demo Paper

When large language models meet personalization: Perspectives of challenges and opportunities
Jin Chen, Zheng Liu, Xu Huang, Chenwang Wu, Qi Liu, Gangwei Jiang, Yuanhao Pu, Yuxuan Lei, Xiaolong Chen, Xingmei Wang, Defu Lian, Enhong Chen
- A survey to summarize the combination of large language models and personlization systems

Fast variational autoencoder with inverted multi-index for collaborative filtering
Jin Chen, Defu Lian, Binbin Jin, Xu Huang, Kai Zhang, Enhong Chen
- An adaptive negative sampler was proposed to training VAE efficiently
⚙️ Projects
- ToolACE: Large Language Models tailored for functional-calling (or tool-using) tasks.
- RecAI: A project aims to bridge this gap by investigating various strategies to integrate LLMs into recommender systems.
- RecFM: A project aims to build foundation models for recommendation systems.
- RecStudio: A modularized and unified library for recommendation system based on PyTorch.
- UniRec: An easy-to-use, lightweight, and scalable implementation of recommender systems.
🎖 Honors and Awards
- Outstanding Graduate of Anhui Province, 2026.04
- Outstanding Graduate of University of Science and Technology of China, 2026.04
- National Scholarship, 2025.12, 2023.12
- USTC Academic Scholarship, 2024.09, 2023.09, 2022.09, 2021.09
- Stars of Tomorrow Award, Microsoft Research Asia, 2023.10
- USTC Excellent Student Prize, 2019.09, 2018.09, 2017.09
- National Encouragement Scholarship, 2018.09
- Shizhang Bei Talent class Scholarship, 2017.09
⏳ Professional Services
Program Committee Members
- Reviewer, IEEE TKDE
- Reviewer, WWW 2024, WWW 2025
- PC member, TrustKDD2023 (workshop)
- PC member, AAAI 2024, 2025
- PC member, KDD 2025
- Sub-Reviewer, CIKM 2023
📃 Curriculum Vitae
Contact me: xuhuangcs@mail.ustc.edu.cn / xu.hwang@outlook.com.