Julien Verlaguet
CEO at Skiplabs
Barcelona, Catalonia, Spain
Summary
🤩
Rockstar🎓
Top SchoolJulien Verlaguet is a seasoned software engineer and CEO based in Barcelona with 16 years of experience building programming languages, developer tools, and performance-critical compiler infrastructure. He led and contributed to influential language projects at Facebook—helping steer Hack and SKIP—and later founded Skiplabs to advance incremental compilation and memoization-driven caching. Julien’s open-source work shows deep compiler and parser expertise, from enhancing PHP parsing in the pfff code-analysis tool to optimizing lexers and LLVM bitcode generation for Skip. Comfortable switching between research-grade language design (FAIR) and production-grade engineering, he blends low-level systems work with product leadership. Notably, he has a track record of turning theoretical language features into practical tooling, such as CLI and server support for incremental builds. Trained in computer science at Pierre and Marie Curie University, he favors pragmatic, performance-focused solutions that scale from developer workflows to distributed systems.
16 years of coding experience
15 years of employment as a software developer
Masters Computer science, Masters Computer science at Pierre and Marie Curie University
Github Skills (19)
parser10
strings10
compiler-development10
text-manipulation10
syntax10
php10
code-analysis10
parsing10
performance-optimization10
parse10
syntax-checking10
llvm9
command-line-interface9
command-line9
type-system9
Programming languages (6)
Github contributions (5)
skiplang/skip
Sep 2018 - May 2022
A programming language to skip the things you have already computed
Role in this project:
Back-end Developer
Back-end DeveloperContributions:255 commits, 218 PRs, 250 pushes in 3 years 7 months
Contributions summary:Julien primarily focused on optimizing the performance of the string literal lexer within the Skip programming language, which involved addressing inefficiencies in substring and special character decoding. They also worked on implementing the initial version of a server to produce LLVM bitcode, enabling incremental compilation and build functionality. Additionally, the user developed the first command-line interface for the Skip compiler, adding essential features for command-line development. Further work included refactoring and simplification of various runtime components.
compilerskipprogramming-languagecomputed
facebookarchive/pfff
May 2011 - Nov 2012
Tools for code analysis, visualizations, or style-preserving source transformation.
Role in this project:Back-end Developer
Back-end DeveloperContributions:40 commits in 1 year 6 months
Contributions summary:Julien's commits primarily involve modifications to PHP code related to code analysis tools. Their contributions include implementing and refining syntax for PHP, specifically concerning strict type declarations and extending the parser to support new data types and structures. They have enhanced the parser with support for features such as type variables, function types, and tuples. The changes touch multiple parts of the codebase, demonstrating a focus on improving the PHP parsing capabilities of the project.
transformationrefactoringvisualizationscode-analysisstatic-analysis
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