I’m a first year master student from Tsinghua University (THU), Shenzhen Graduate School. My advisor is Prof. Yujiu Yang. Prior to this, I obtained my bachelor’s degree from the Department of Electronic Engineering at Tsinghua University in June 2025.

I am currently interning in ByteDance, focusing on post-training of MLLM for e-commerce scenarios. Prior to this, I interned in TeleAI, working on the post-training of the Telechat series foundation models. I have also interned in Tencent before for kernel development.

My research interest includes Reward Model/LLM-as-a-Judge and LLM/MLLM post training.

Activities

• 2025.9 📖 I enroll in the Shenzhen Graduate School of Tsinghua University to pursue a Master degree, with an expected graduation date in 2028.
• 2025.8 🎉 Improve llm-as-a-judge ability as a general ability is accepted by EMNLP 2025 Main Conference. Welcome to use our SOTA LLM-as-a-Judge model RISE-Judge!
• 2025.6 🎆 I graduate from Department of Electronic Engineering, Tsinghua University and get bachelor degree.
• 2025.4 💼 I begin an internship at ByteDance, focusing on MLLM post-training research.

Publications

• Improve llm-as-a-judge ability as a general ability
  • Jiachen Yu^*, Shaoning Sun^*, Xiaohui Hu, Jiaxu Yan, Kaidong Yu, Xuelong Li
  • EMNLP 2025 Main Conference
  • Finished during internship in TeleAI.

Preprints

• VFaith: Do Large Multimodal Models Really Reason on Seen Images Rather than Previous Memories?
  • Jiachen Yu^*, Yufei Zhan^*, Ziheng Wu, Yujiu Yang, Yousong Zhu, Jinqiao Wang
  • Finished during internship in ByteDance.
• S2J: Bridging the Gap Between Solving and Judging Ability in Generative Reward Models
  • Shaoning Sun^*, Jiachen Yu^*, Zongqi Wang, Xuewei Yang, Tianle Gu, Yujiu Yang

Internship

• 2025.4-Now: Bytedance, Data, Global E-commerce
• 2024.10-2025.3: TeleAI
• 2024.6-2024.8: Tencent, TEG

Interests

• Riding, city walk, Running
• Computer Card Games (HearthStone et al.)