Runxin Xu
Also known as 许润昕
Runxin Xu is a researcher at DeepSeek who works on large language models. They earned a bachelor's degree at Shanghai Jiao Tong University in 2020 and a master's degree in 2023 at Peking University's Institute of Computational Linguistics, advised by Baobao Chang and Zhifang Sui. After joining DeepSeek in August 2023, they coauthored DeepSeekMoE, DeepSeekMath, DeepSeek-V2 and DeepSeek-V3 in 2024, and the DeepSeek-V4 report in 2026. They were a core contributor to DeepSeek-R1, whose paper Nature published in September 2025.
Timeline
-
2016–2020
Engineering degree at Shanghai Jiao Tong
Between 2016 and 2020, they study for a B.Eng. in the School of Cyber Science and Engineering at Shanghai Jiao Tong University.
-
2019–2021
Internships at ByteDance and Alibaba
They are a research intern at ByteDance AI Lab from November 2019 to January 2021, working on information extraction and machine translation. In 2021, they intern at Alibaba DAMO Academy on effective and efficient language models.
-
2020–2023
Master's at Peking University
In 2020, they begin an M.S. in the School of EECS at Peking University, working in the Institute of Computational Linguistics under Baobao Chang and Zhifang Sui. They finish the degree in 2023.
-
August 2023
Joining DeepSeek as a researcher
In August 2023, they join DeepSeek as a researcher working on large language models.
-
2024
DeepSeekMoE and DeepSeekMath
In February 2024, they coauthor DeepSeekMath, whose paper introduces Group Relative Policy Optimization (GRPO) and a data selection pipeline for publicly available web data. They are also an author of DeepSeekMoE, published at ACL 2024.
-
May 2024–December 2024
DeepSeek-V2 and DeepSeek-V3
In May 2024, they are among the authors of DeepSeek-V2, a Mixture-of-Experts model with 236B total parameters and 21B activated for each token. In December 2024, they are among the authors of DeepSeek-V3, which has 671B total parameters with 37B activated for each token.
-
September 2025
DeepSeek-R1 in Nature
Nature publishes the DeepSeek-R1 paper in September 2025, and Runxin Xu is listed among its core contributors. The paper shows that the reasoning abilities of LLMs can be incentivized through pure reinforcement learning (RL).
-
As of October 2026
Researcher at DeepSeek
They are a researcher at DeepSeek, working on large language models. In 2026, Runxin Xu is among the authors of the DeepSeek-V4 report, which presents two Mixture-of-Experts models, V4-Pro with 1.6T parameters and V4-Flash with 284B parameters, both supporting a context length of one million tokens.
Career
- Since 2023DeepSeekResearcher
- 2025–2026Shanghai Jiao Tong University
- 2022–2023Imperial College London
- From 2021AlibabaIntern
- 2019–2021ByteDanceResearch intern
Education
- 2023Peking UniversityM.S.
- 2020Shanghai Jiao Tong UniversityB.Eng.
Most-cited works
- DeepSeek-R1 incentivizes reasoning in LLMs through reinforcement learningWith Bingxuan Wang, Chengqi Deng, Damai Dai, Daya Guo, Erhang Li and Fangyun Lin
- Can Open Large Language Models Catch Vulnerabilities?With Bingxuan Wang, Chengqi Deng, Damai Dai, Erhang Li, Fangyun Lin and Haocheng Wang
- DeepSeek-V3 Technical ReportWith Bingxuan Wang, Chengqi Deng, Damai Dai, Daya Guo, Dejian Yang and Erhang Li
- Double Graph Based Reasoning for Document-level Relation Extraction
- Raise a Child in Large Language Model: Towards Effective and Generalizable Fine-tuningWith Fei Huang
Sources and credits
Photo: We have no published photo of Runxin Xu yet. Send us a free-licensed photo.
- Runxin Xu (许润昕)
- Runxin Xu | alphaXiv
- [2402.03300] DeepSeekMath: Pushing the Limits of Mathematical Reasoning in Open Language Models
- [2405.04434] DeepSeek-V2: A Strong, Economical, and Efficient Mixture-of-Experts Language Model
- [2412.19437] DeepSeek-V3 Technical Report
- DeepSeek-R1 incentivizes reasoning in LLMs through reinforcement learning | Nature
- [2606.19348] DeepSeek-V4: Towards Highly Efficient Million-Token Context Intelligence

