Dr. Steven Costiou

Research scientist Inria
I am a research scientist at Inria in RMoD, an Inria team member of the CRISTtAL laboratory (UMR CNRS 9189).
Keywords: Debugging, Live Debugging, Object-Centric Debugging, Time-travel Debugging, Scriptable Debuggers, Dynamic Langages, Reflection, Software Adaptation, Object-Oriented Systems, Software Engineering.


I build and study tools to help developers understand and fix bugs in their programs. To that end, first I try to identify the best techniques applicable to the investigation of hard bugs. Second, I try to identify and to study the properties that programming languages and their infrastructures should expose to support those debugging techniques. For some problems, especially real world problems, these techniques do not exist and I must define them. I build tools to prove the feasibility of these techniques and their applicability to the target problem. I then empirically evaluate them to study and to understand their impact on the debugging activity. Finally, I transfer the most advanced and promising tools to the open-source and industry worlds.


PhD students

Master 2

Master 1


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Student volunteer