Hadrien Croubois
Smart Contracts Engineer at OpenZeppelin
Lyon, Auvergne-Rhône-Alpes, France
Summary
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Rockstar🎓
Top SchoolHadrien Croubois is an Engineering Manager and Solidity expert with 13 years of experience bridging distributed-systems research and production-grade smart contract engineering. A Normalien with a PhD in distributed systems, he has been a core contributor at OpenZeppelin—implementing critical upgradeability patterns (UUPS, ERC-1967), timelock controllers, and secure deployment workflows used widely across the Ethereum ecosystem. He previously translated research into real-world blockchain primitives at iExec and has deep expertise in test automation, security, and upgrade-safe storage layouts for on-chain code. Based in Lyon, he combines academic rigor with pragmatic security-first development, and quietly stands out for turning complex formal ideas about validation and resiliency into practical tooling and contracts relied upon by the community.
13 years of coding experience
2 years of employment as a software developer
L3 & M1, Informatique fondamentale, L3 & M1, Informatique fondamentale at Ecole normale supérieure de LyonMPSI - MP*, MPSI - MP* at Lycée Saint-LouisBac S, S-SVT, TB, Bac S, S-SVT, TB at LFIT (anciennement LFJT)M2 recherche, Informatique - IGI, Mention Bien, M2 recherche, Informatique - IGI, Mention Bien at Université Claude Bernard Lyon 1
French, English, Japanese, Spanish
Stackoverflow
3,020reputation
264kreached
50answers
57questions
Github Skills (18)
solidity10
testing10
evm10
security10
ethereum10
blockchain10
smart-contracts10
erc72110
hardhat10
erc209
truffle8
vector6
constants6
multithreading6
boolean6
Programming languages (14)
Github contributions (5)
OpenZeppelin/workshops
Feb 2021 - Jan 2022
Code and slides for OpenZeppelin Workshops
Role in this project:
Back-end Developer & Test Automation Engineer
Back-end Developer & Test Automation EngineerContributions:12 commits, 4 PRs, 22 pushes in 10 months
Contributions summary:Hadrien primarily worked on smart contract development within the OpenZeppelin Workshops repository, focusing on the Argent wallet factory and ERC20 token implementations. They added and modified Solidity code related to wallet creation and testing ERC20 functionality. The user also contributed to testing and deployment scripts, with a focus on lazy minting and ERC721 contracts.
openzeppelin
OpenZeppelin/openzeppelin-contracts
Sep 2020 - Jan 2023
OpenZeppelin Contracts is a library for secure smart contract development.
Role in this project:Back-end Developer
Back-end DeveloperContributions:6 releases, 3079 reviews, 308 commits in 2 years 4 months
Contributions summary:Hadrien implemented the `TimelockController` contract, including features such as queuing and executing transactions with a delay, and handling permissions. Their work included designing a system for storing and managing operations. They also added functionality to handle the minting of tokens in multiple steps.
securesmart-contractethereumsecuritycontract
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