Lucas Franceschino
Founding Software Engineer at The Forecasting Company
Greater Paris Metropolitan Region France
Summary
🤩
Rockstar🎓
Top SchoolLucas Franceschino is a founding software engineer with 11 years of experience building formal verification toolchains and production-grade cryptographic software. Currently leading The Forecasting Company, he previously designed and led Cryspen’s hax toolchain that translates large subsets of Rust into proof languages like F* and Coq, and drove a rewrite of the engine from OCaml to Rust. His work at Cryspen produced formally verified cryptographic Rust code now deployed at Mozilla and Google and was presented at RWC 2025, underscoring a rare combination of deep research and practical impact. He contributed significant core-language work to the F* project—improving reflection, embeddings and parser features—which complements his experience bridging Rust compiler internals to formal backends. Comfortable across Rust, OCaml, React and CI/Nix-based deployment, he also builds developer tooling and large-scale testing infrastructures (including experiments across 10k crates). Trained as a doctoral researcher in mathematics and computer science, he blends rigorous formal methods with pragmatic engineering to ship auditable, high-assurance systems.
11 years of coding experience
Licence Mathématiques et informatique, Licence Mathématiques et informatique at University of MontpellierMaster of Science (M.Sc.) Mathématiques et informatique, Master of Science (M.Sc.) Mathématiques et informatique at Radboud Universiteit NijmegenBaccalauréat Spécialité Mathématiques, Baccalauréat Spécialité Mathématiques at Lycée Georges PompidouDoctorat Mathématiques et informatique, Doctorat Mathématiques et informatique at INRIA
French, English, Spanish
Github Skills (10)
programming-language10
fs10
dependent-types10
f10
fstar10
parsing9
parse9
parser9
theorem-proving9
ocaml8
Programming languages (13)
Github contributions (5)
FStarLang/FStar
Jun 2019 - Nov 2022
A Proof-oriented Programming Language
Role in this project:
Back-end Developer
Back-end DeveloperContributions:19 reviews, 94 commits, 38 PRs in 3 years 6 months
Contributions summary:Lucas primarily contributed to the reflection and embedding aspects of the F* language, modifying core files related to reflection, embeddings, and data structures. They refactored and extended the language parser by adding support for monadic lets and matches, as well as operators. Additionally, the user made adjustments to handle type ascriptions within monadic let bindings and record expressions, improving the language's syntax and features.
homotopy-type-theorycoq-librarytype-theorysat-solvercompiler
cryspen/hax
Jan 2023 - Mar 2023
A Rust verification tool
Contributions:3 releases, 523 reviews, 117 commits in 1 month
formal-verificationrust
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