I am a senior researcher at Google Research in the Systems Research Group, and a PhD student at UC Berkeley in the NetSys lab, advised by Sylvia Ratnasamy. My research interests are in building reliable self-improving control systems. I have worked on formal verification, input validation, and decentralized architectures for global-scale networks. More recently, I've focused on agentic systems that improve their own code and behavior. My work at Google focuses on architecting network control systems and reasoning rigorously about their correctness and performance. My work at Berkeley has spanned control systems for self-driving cars and AI-driven scientific discovery.
I received a B.S. in EECS and a B.A. in Music from UC Berkeley in 2019, and am supported by an NSF CSGrad4US Fellowship.
My non-academic personal site is also here, and my blog is on Substack here.
I am drawn to problems that touch on control systems, decentralization, and usable and practical systems, which taken together have led me to networking. I enjoy systems thinking and the problems that come along with it. Outside of systems, I am very interested in computer science education and pedagogy.
Reality Is the Final Verifier: On Two Key Gaps in Agentic Software Engineering
Alexander Krentsel*, Shubham Agarwal*, Mert Cemri*, Shu Liu*, Sidharth Sankhe, Ziming Mao, Matei Zaharia, Ion Stoica.
Exoharness: An Agent Harness Architecture for Fully-Recursive Self-Improvement
Alexander Krentsel, Ankur Goyal, Martin Casado.
Open Source Project
[ GitHub | Website ]
Invariant Discovery for Networked Systems
Hongyu He, Alexander Krentsel, Sylvia Ratnasamy, Maria Apostolaki.
Under Submission
[ Arxiv ]
Transport It Your Way: Rethinking Networking Projects to Emphasize Design
Alexander Krentsel*, Tess Despres*, Sylvia Ratnasamy.
SIGCOMM '26: Workshop on AI for Networking Education (A4NE '26)
[ Paper | Workshop ]
Ludwig: Autonomous Multilingual Synthesis of Correct, Engaging Explainer Videos
Alexander Krentsel.
SIGCOMM '26: Workshop on AI for Networking Education (A4NE '26)
[ Paper | Workshop ]
Adaptive Failure Taxonomies as Feedback for LLM-Agent Improvement Procedures
Mert Cemri, Andrei Cojocaru, Melissa Pan, Shu Liu, Shubham Agarwal, Alexander Krentsel, Jay Tang, Kannan Ramchandran, Joseph E. Gonzalez, Matei Zaharia, Alexandros G. Dimakis, Ion Stoica.
ICML '26 Workshop: Failure Modes in Agentic AI
[ Workshop ]
Spilling the TE: Lessons from AI-driven evolution of Traffic Engineering
Rahul Bothra, Alexander Krentsel, Brighten Godfrey, Sylvia Ratnasamy.
CAIS '26 Workshop: AI Agents for Discovery in the Wild
[ Paper | Workshop ]
⭐ Inductive Deductive Synthesis: Enabling AI to Generate Formally Verified Systems
Shubham Agarwal*, Alexander Krentsel*, Shu Liu*, Mert Cemri*, Audrey Cheng, Rui Meng, Tomas Pfister, Chun-Liang Li, Sylvia Ratnasamy, Aditya Parameswaran, Matei Zaharia, Ion Stoica, Mohsen Lesani.
Under Submission
[ Arxiv ]
Not Too Soon for Just-in-Time Systems: Challenges and Opportunities
Shu Liu*, Alexander Krentsel*, Shubham Agarwal*, Mert Cemri*, Ziming Mao, Soujanya Ponnapalli, Alexandros G. Dimakis, Sylvia Ratnasamy, Aditya Parameswaran, Ion Stoica.
Under Submission, Conference paper
[ Arxiv ]
⭐ CrossCheck: Input Validation for WAN Control Systems
Alexander Krentsel, Bharath Modhipalli, Rishabh Iyer, Isaac Keslassy, Sylvia Ratnasamy, Anees Shaikh, Rob Shakir.
NSDI 2026, Renton, WA
[ Paper | Slides | Video ]
GATE: GPU-Accelerated Traffic Engineering for the WAN
Rahul Bothra, Alexander Krentsel, Saptarshi Mandal, Brighten Godfrey, Sylvia Ratnasamy, Rob Shakir, R. Srikant.
Under Submission, Conference paper
[ Paper ]
SkyDiscover: A Flexible Framework for AI-Driven Scientific and Algorithmic Discovery
Shu Liu*, Mert Cemri*, Shubham Agarwal*, Alexander Krentsel, et. al..
Open Source Project
[ GitHub | Blog Post | CAIS '26 Demo ]
⭐ TURBO: Utility-Aware Bandwidth Allocation for Cloud-Augmented Autonomous Control
Peter Schafhalter*, Alexander Krentsel*, Hongbo Wei, Joseph E. Gonzalez, Sylvia Ratnasamy, Scott Shenker, Ion Stoica.
NINeS 2026, Virtual
[ Paper | Slides | Video | Conference Program ]
⭐ Towards Accessible Model-Free Verification
Alexander Krentsel, Oliver Ye, Anthony Tafoya, Xuqian Ma, Sylvia Ratnasamy, Anees Shaikh.
HotNets 2025, College Park, MD
[ Paper | Slides | Conference Program ]
Barbarians at the Gate: How AI is Upending Systems Research
Audrey Cheng, Shu Liu, Melissa Pan, Zhifei Li, Bowen Wang, Alexander Krentsel, Tian Xia, Mert Cemri, Jongseok Park, Shuo Yang, Jeff Chen, Lakshya Agrawal, Aditya Desai, Jiarong Xing, Koushik Sen, Matei Zaharia, Ion Stoica.
Arxiv 2025, Under Submission, Conference paper
[ Arxiv ]
The Case for Validating Inputs in Software-Defined WANs
Alexander Krentsel, Rishabh Iyer, Isaac Keslassy, Sylvia Ratnasamy, Rob Shakir, Anees Shaikh.
HotNets 2024, Irvine, CA
[ Paper | Slides | Video | Conference Program ]
Managing Bandwidth: The Key to Cloud-Assisted Autonomous Driving
Alexander Krentsel*, Peter Schafhalter*, Joseph E. Gonzalez, Sylvia Ratnasamy, Scott Shenker, Ion Stoica.
[ Arxiv ]
⭐ A Decentralized SDN Architecture for the WAN
Alexander Krentsel, Nitika Saran, Bikash Koley, Subhasree Mandal, Ashok Narayanan, Sylvia Ratnasamy, Ali Al-Shabibi, Anees Shaikh, Rob Shakir, Ankit Singla, Hakim Weatherspoon.
SIGCOMM 2024, Sydney, Australia
[ Paper | Slides | Video | Poster | Patent 1 | Patent 2 | Conference Program ]
The Sky is the Limit: Cloud-Assisted Autonomous Driving via Service Tiers
Alexander Krentsel, Peter Schafhalter, Joseph E. Gonzalez, Sylvia Ratnasamy, Scott Shenker, Ion Stoica.
Compound AI Systems Workshop, Databricks Data + AI Summit 2024
[ Extended Abstract | Poster | Workshop Program ]
CrossCheck: Input Validation for WAN Control Systems [ Slides | Video ]
Principles for Autonomous System Design: OpenClaw Deepdive [ Slides | Video ]
Decentralizing Software Defined Networking: The Hidden Complexities of SDN & What We Can Do About Them [ Slides | Video ]
Towards Accessible Model-Free Verification [ Slides ]
The Case for Validating SDN Inputs [ Slides | Video ]
Narrative Building for Career Pivots [ Slides ]
Grad School 101: What, Why, and How [ Slides ]
Decentralizing the SDN WAN Control Plane [ Slides ]
From Google to Berkeley PhD, Systems Research, and Teaching [ Video ]
Lessons Learned from a 10-Year Cal Journey [ Slides ]
How to Write Letters of Recommendation [ Slides ]
Ethics Questions are Everywhere in Computer Science [ Slides ]
Outside of research and teaching, I occasionally perform on violin with friends in classical and contemporary ensembles. I also spent a year conducting ethnomusicology fieldwork as a violinist embedded in an Arabic band, which I wrote up in an article, Politics of the Apolitical in Post-Tarab Spaces.