About Me

I am a PhD student at the National University of Singapore (NUS), where I am advised by Prof. Abhik Roychoudhury. My research focuses on Autonomous Software Engineering, combining program analysis with Large Language Models to build coding agents that are effective, trustworthy, and secure. I also work on analysis-based automated program repair and software security.

My research on the LLM agent AutoCodeRover led to a startup spin-off on autonomous coding agents. Our startup was later acquired by Sonar in 2025. Following the acquisition, I'm currently a part-time Research Consultant at Sonar.

Research Directions

LLM Agents for Software Engineering

  • AutoCodeRover agent for program improvement:
    • Program analysis for code search (code structure-based search, statistical fault localization). [ISSTA'24]
    • Improve signal-to-noise ratio of agent-generated code. [ICSE'25]
    • Context enrichment through program analysis for vulnerability repair. [ICSE'26-SEIP]
    • Research Impact: This research led to the founding of the startup AutoCodeRover, which was acquired by Sonar. Press Release News
  • General coding agent with software engineering grouded action space. [ICSE'26]

Automated Program Repair

  • Inferring patch constraints with dynamic analysis and inductive inference. [ISSTA'22]
  • Static analysis summaries to guide patch generation. [TOSEM'25]
  • Fuzzing-based search to explore the space of program patches. [arXiv]

Publications Google Scholar

PDFs are for personal use only and not for redistribution.
ICSE'26
Unified Software Engineering agent as AI Software Engineer
PDF Code
Leonhard Applis*, Yuntong Zhang*, Shanchao Liang, Nan Jiang, Lin Tan, Abhik Roychoudhury
(*Joint first authors, ordered alphabetically.)
48th International Conference on Software Engineering (ICSE)
ICSE'26-SEIP
Fixing Security Vulnerabilities with Agentic AI in OSS-Fuzz
PDF
Yuntong Zhang, Jiawei Wang, Dominic Berzin, Martin Mirchev, Abhik Roychoudhury
48th International Conference on Software Engineering (ICSE), SEIP Track
ICSE'25
SpecRover: Code Intent Extraction via LLMs
PDF Code
Haifeng Ruan*, Yuntong Zhang*, Abhik Roychoudhury
(*Joint first authors, ordered alphabetically.)
47th International Conference on Software Engineering (ICSE)
TOSEM'25
EffFix: Efficient and Effective Repair of Pointer Manipulating Programs
PDF Code
Yuntong Zhang, Andreea Costea, Ridwan Shariffdeen, Davin McCall, Abhik Roychoudhury
ACM Transactions on Software Engineering and Methodology (TOSEM)
ISSTA'24
AutoCodeRover: Autonomous Program Improvement
PDF Code
Yuntong Zhang, Haifeng Ruan, Zhiyu Fan, Abhik Roychoudhury
33rd ACM SIGSOFT International Symposium on Software Testing and Analysis (ISSTA)
arXiv
Program Repair by Fuzzing over Patch and Input Space
PDF
Yuntong Zhang, Ridwan Shariffdeen, Gregory J Duck, Jiaqi Tan, Abhik Roychoudhury
arXiv preprint (2023)
ISSTA'22
Program Vulnerability Repair via Inductive Inference
PDF Code
Yuntong Zhang, Xiang Gao, Gregory J. Duck, Abhik Roychoudhury
31st ACM SIGSOFT International Symposium on Software Testing and Analysis (ISSTA)
EuroSys'22
Hardening Binaries against More Memory Errors
PDF Code
Gregory J. Duck, Yuntong Zhang, Roland H. C. Yap
Seventeenth European Conference on Computer Systems (EuroSys)

Talks

Apr 2025
Columbia University COMS 6113: Invited talk on Coding Agents in the PhD-level course Agentic Systems Made Real.
Jan 2025
Shonan Meeting 217: Trusted Automatic Programming. Presented the latest development of the AutoCodeRover agent.
Aug 2024
Microsoft Data&AI: Presented AutoCodeRover and SpecRover.
May 2024
Machine Learning Singapore: Presented AutoCodeRover at the Code and Vision meet Art and Efficiency event.

Academic Services

Program Committee
Next-Gen Code Development with Collaborative AI Agents @ AAAI 2026.
Reviewer
IEEE Transactions on Software Engineering (TSE).
ACM Transactions on Software Engineering and Methodology (TOSEM).
Empirical Software Engineering (EMSE).
Student Volunteer
ESEC/FSE 2022.