mathias lecuyer

CS PhD student @ Columbia University


Mathias Lecuyer
I am a French New Yorker, and Computer Science student at Columbia University. Among many other things, I like to build stuff, learn new programming languages, travel, and do rock climbing. I also love to read, on topics ranging from econ to history and policy.


My research interests are very broad. I currently focus on distributed systems, and specifically how to promote responsible data management and transparency. I am also interested in decentralized systems, crypto currencies, and the sharing economy.


To add transparency to data uses on the Web, I am building a series of scalable, generic, and reliable tools to detect data flows within and across web services. My initial system, XRay, offers a first system design and theoretical building blocks to detect the use of digital personal data for targeting and personalization. The key insight in XRay is to infer targeting by correlating user inputs (such as searches, emails, or locations) to service outputs (such as ads, recommendations, or prices) based on observations obtained from user profiles populated with different subsets of the inputs. My latest tool, Sunlight, leverages rigorous statistical methods to determine not only the correlations, but more significantly the causes of online targeting at great scale and based on solid statistical justification.