Cristian Zamfir

Guest Research Assistant
School of Computer and Communication Sciences
INN 319
Station 14
1015 Lausanne, Switzerland
Contact:, LinkedIn

I am currently a co-founder and COO at Cyberhaven, a stealth-mode security startup developing a radical new way to ensure the safety and security of IT assets.

I was a postdoctoral researcher and got my PhD from EPFL, in the in the Dependable Systems Lab. My adviser was Professor George Candea. My PhD thesis focused on building execution synthesis, an automated debugging technique that starts from a bug report and automatically synthesizes an execution that reproduces the respective bug, without recording the execution of the program while it runs in production. Using a combination of static analysis and symbolic execution, it “synthesizes” the thread schedule and the program inputs that cause the bug to manifest. The synthesized execution can be played back automatically in regular debuggers.

During my third year of PhD I spent five months at UC Berkeley in the RADLab working with Prof. Ion Stoica and Gautam Altekar on replay-debugging for data center applications.

Before starting my PhD, I was involved in various areas of computer systems. I worked on live migration of virtual machine storage at University of Glasgow, on a background transfer service for TCP at Microsoft Research Cambridge, on preventing shilling attacks in recommender systems at L3S Research Center, and on wireless routing for vehicular networks at NJIT.

I received my MSc in computer science from University of Glasgow in 2007 and my BS from University Politehnica of Bucharest in 2005.

For more details, see Curriculum Vitae: [PDF]


  1. Automated Classification of Data Races for Both Strong and Weak Memory Models, Baris Kasikci, Cristian Zamfir, and George Candea. In Transactions of Programming Languages and Systems (TOPLAS), May 2015.
  2. RaceMob: Crowdsourced Data Race DetectionBaris Kasikci, Cristian Zamfir, and George Candea. 24th Symposium on Operating Systems Principles (SOSP), Farmington, PA, November 2013.
  3. CodeTickler: Automated Software Testing as a Service, Cristian Zamfir, Vitaly Chipounov, George Candea. Workshop on High Performance Transaction Systems (HPTS), Pacific Grove, CA, September 2013.
  4. Automating the Debugging of Datacenter Applications with ADDACristian Zamfir, Gautam Altekar, and Ion Stoica. Intl. Conference on Dependable Systems and Networks (DSN), Budapest, Hungary, June 2013.
  5. Automated Debugging for Arbitrarily Long Executions. Cristian Zamfir, Baris Kasikci, Johannes Kinder, Edouard Bugnion, and George Candea. Workshop on Hot Topics in Operating Systems (HotOS), Santa Ana Pueblo, NM, May 2013.
  6. Reconstructing Core DumpsJeremias Rößler, Andreas Zeller, Gordon Fraser, Cristian Zamfir, and George Candea. IEEE International Conference on Software Testing, Verification and Validation (ICST), Luxembourg, March 2013.
  7. CoRD: A Collaborative Framework for Distributed Data Race DetectionBaris Kasikci, Cristian Zamfir, and George Candea. 8th Workshop on Hot Topics in System Dependability (HotDep), Hollywood, CA, October 2012.
  8. Data Races vs. Data Race Bugs: Telling the Difference with Portend, Baris Kasikci, Cristian Zamfir, and George Candea, Intl. Conference on Architectural Support for Programming Languages and Operating Systems (ASPLOS), London, UK, March 2012.
  9. Debug Determinism: The Sweet Spot for Replay-Based DebuggingCristian Zamfir, Gautam Altekar, George Candea, Ion Stoica, in 11th Workshop on Hot Topics in Operating Systems (HotOS), Napa, CA, May 2011.
  10. Parallel Symbolic Execution for Automated Real-World Software TestingStefan Bucur, Vlad Ureche, Cristian Zamfir, George Candea. 6th ACM SIGOPS/EuroSys European Conference on Computer Systems (EuroSys), Salzburg, Austria, April 2011.
  11. Low-Overhead Bug Fingerprinting for Faster Debugging. Cristian Zamfir and George Candea. 1st Intl. Conference on Runtime Verification (RV), Malta, November 2010.
  12. Automated Software Testing as a ServiceGeorge Candea, Stefan Bucur, Cristian Zamfir. 1st ACM Symposium on Cloud Computing (SOCC), Indianapolis, IN, June 2010. 
  13. Execution Synthesis: A Technique for Automated Software DebuggingCristian Zamfir and George Candea. 5th ACM SIGOPS/EuroSys European Conference on Computer Systems (EuroSys), Paris, France, April 2010.
  14. Cloud9: A Software Testing Service, Liviu Ciortea, Cristian Zamfir, Stefan Bucur, Vitaly Chipounov, George Candea, in ACM Operating Systems Review, Vol. 43, No. 4, December 2009 (also in  Proc. of the 3rd ACM Intl. Workshop on Large Scale Distributed Systems and Middleware (LADIS), Big Sky, MT, Oct. 2009).
  15. Selective Symbolic Execution, Vitaly Chipounov, Vlad Georgescu, Cristian Zamfir, George Candea, in Proceedings of the 5th Workshop on Hot Topics in System Dependability (HotDep), Lisbon, Portugal, June 2009.
  16. Deadlock Immunity: Enabling Systems To Defend Against Deadlocks, Horatiu Jula, Daniel Tralamazza, Cristian Zamfir, George Candea, in Proceedings of the 8th USENIX Symposium on Operating Systems Design and Implementation (OSDI), San Diego, CA, December 2008.
  17. Live Migration of User Environments Across Wide Area Networks, Cristian Zamfir, Master Thesis, University of Glasgow, UK 2009.
  18. Preventing Shilling Attacks in Online Recommender Systems, Paul-Alexandru Chirita, Wolfgang Nejdl, Cristian Zamfir, in Proceedings of the 7th ACM International Workshop on Web Information and Data Management (WIDM - held at the 14th ACM International Conference on Information and Knowledge Management (CIKM), Bremen, Germany. 2005.
  19. An Efficient Electronic Cash Platform for Smart Phones, Cristian Zamfir, Ionut Constandache, Andrei Damian, Valentin Cristea, in Proceedings of the ECOMM-LINE International Conference, Bucharest, Romania, 2004.



Work In Progress and Posters

  1. Automating the Debugging of Datacenter Applications with ADDA, Gautam Altekar, Cristian Zamfir, George Candea, Ion Stoica, Technical Report No. UCB/EECS-2011-22, April 4, 2011.
  2. DDB: Deadlock Debugger [poster] [abstract], poster at the 3rd ACM EuroSys Conference, Glasgow, Scotland, April 2008.
  3. Live Migration of Virtual Block Devices [poster] [abstract], Cristian Zamfir, Colin Perkins, Peter Dickman, poster at the 2nd ACM EuroSys Conference Lisbon, Portugal, 2007.


Guitar playing and singing [SoundCloud] [], [mx3] and [myspace], Rock climbing, Table tennis.