Quis custodiet ipsos custodes: Towards Trustworthy Software Guardians

23^rd June 2026, 13:00 Ashton Lecture Theatre
Chengyu Zhang
Loughborough University

Abstract

Modern software systems are increasingly complex, relying on a diverse spectrum of automated "guardians" for quality assurance. These guardians range from foundational formal logic engines and rigorous program analysers to AI guardrails. However, a fundamental issue remains: these guardians are themselves intricate software systems, yet there is a severe lack of effective technologies to guarantee their own quality. This talk explores a classical philosophical question within the realm of software reliability: Who guards the guardians? This talk will illustrate how defects can undermine these critical tools and introduce novel technologies to effectively identify and mitigate them.

Biography

Chengyu Zhang is a Lecturer in the Department of Computer Science at Loughborough University. He was previously a postdoctoral researcher at ETH Zurich. His research spans software engineering, programming languages, and formal methods, with a focus on providing solutions to ensure the reliability of modern software. His research has uncovered over 2,000 bugs in real-world software systems and has resulted in more than 15 publications in top-tier venues. He has served as a Co-Chair of the PLDI, OSDI, and USENIX ATC Artifact Evaluation committees, a Program Committee member for ICSE, FSE, ASE, OOPSLA, and ISSTA, receiving a Distinguished Reviewer Award, and a reviewer for TOSEM, TSE, and TOPLAS. His work has been recognised by a PLDI Distinguished Paper Award and a Google Open Source Peer Bonus, and supported by an Amazon Research Award and the CCF-ANT Research Award.