Before moving into industry (and later into education), I did a PhD under Olivier Ridoux at IRISA, followed by a postdoc in the Coccinelle project under Julia Lawall and Gilles Muller. Semgrep’s pattern-matching approach traces back to that work.
Full list: DBLP
Understanding Collateral Evolution in Linux Device Drivers. Yoann Padioleau, Julia L. Lawall, Gilles Muller. EuroSys 2006, Leuven, Belgium. pdf
Code: the Coccinelle project (with Julia Lawall and Gilles Muller) — the semantic-patch tool that grew out of this work, and whose pattern-matching style later informed Semgrep.
A Logic File System (PhD thesis topic). Yoann Padioleau, Olivier Ridoux. USENIX Annual Technical 2003, San Antonio, Texas. pdf · PhD thesis (French): pdf
Code: lfs, the logic file system from the paper.
Parsing C/C++ Code without Preprocessing. Yoann Padioleau. CC 2009, York, United Kingdom. pdf
Code: yacfe (Yet Another C Front-End) and pfff, the style-preserving C/C++ parsing and transformation libraries this paper is based on — ancestors of today’s semgrep-pfff-libs / semgrep-pfff-langs.