--- title: Julien Béranger — Smart Contract & Full-Stack Engineer description: Julien Béranger's CV. date: 2026-09-17 lang: en-US author: Julien Béranger model: Claude Sonnet 5 conversation: https://claude.ai/chat/41c9b472-71ed-4488-a56b-6959f5f88cd7 source: https://julienberanger.com/julien-cv-sept-2026 --- # Julien Béranger — Smart Contract & Full-Stack Engineer ## Profile Full-stack and smart contract developer with 6+ years of production experience, most of it on [Solidity](https://soliditylang.org/) and the [Ethereum Virtual Machine](https://ethereum.org/en/developers/docs/evm/) (EVM). Experienced in designing token registries and on-chain issuance systems for institutions (including a registry built for [AFNIC](https://www.afnic.fr/), which manages 4 million .fr domain names), an expert in [Foundry](https://getfoundry.sh/) for contract testing (fuzzing, invariants), and comfortable working on permissioned EVM chains and their upgradeable system contracts. Fluent English, used daily in international settings. ## Key skills - **Solidity & EVM**: design and development of smart contracts in [Solidity](https://soliditylang.org/), using [OpenZeppelin](https://www.openzeppelin.com/) libraries for token standards (including [ERC-20](https://eips.ethereum.org/EIPS/eip-20)) and NFTs. - **Advanced testing**: [Foundry](https://getfoundry.sh/) expert — fuzz testing and invariant testing are at the core of my day-to-day practice — complemented by [Jest](https://jestjs.io/) integration tests and [CI/CD](https://en.wikipedia.org/wiki/CI/CD) pipelines. - **Security & robustness**: at [Arthera](https://arthera.net/), improved the core protocol through load-testing campaigns and upgrades to upgradeable system contracts; designed privacy-preserving APIs using [zero-knowledge proofs](https://en.wikipedia.org/wiki/Zero-knowledge_proof) at [W3HC](https://github.com/w3hc). - **Enterprise EVM chains**: solid conceptual understanding of permissioned EVM architectures such as [Hyperledger Besu](https://besu.hyperledger.org/); familiar with the [Canton Network](https://www.canton.network/) and its [Zenith](https://zenith.network) EVM execution layer, whose privacy-by-partitioning approach echoes the anonymous-API work done at W3HC — able to ramp up quickly on both stacks where needed, using standard Solidity tooling (Foundry, Ethers.js) against Zenith's EVM-compatible RPC. - **Web3 tooling**: [Ethers.js](https://docs.ethers.org/), [Viem](https://viem.sh/), [Wagmi](https://wagmi.sh/), [Reown](https://reown.com/). - **English**: daily working language (technical documentation, workshops, support for international developers). ## Professional experience ### CEO & Lead Developer — [Strat](https://strat.cc/) (2020 – present) - Designed an NFT registry for [AFNIC](https://www.afnic.fr/), the institution managing 4 million .fr domain names — direct, hands-on experience issuing tokens for an institutional trusted third party. - Developed several Web3 projects for [Kleros](https://kleros.io/) and Hexarchia. - Delivered a custom RAG system for Systemlog (5,000+ monthly active users). - Won 1st prize at the DAO Global Hackathon 2022, [Core DAO](https://coredao.org/) technical track. - Ran Web3 hackathons for [UNESCO](https://www.unesco.org/) and Paris 8 University; trained students at [Epitech](https://www.epitech.eu/), STUDI, and [emlyon business school](https://em-lyon.com/). ### Co-founder & Lead Developer — [W3HC](https://github.com/w3hc) (February 2023 – present) - [ZK API](https://github.com/w3hc/zk-api): TypeScript implementation of a zero-knowledge cryptography research proposal, enabling anonymous API access — an approach directly transferable to the privacy requirements of a network like Canton. - [w3pk](https://w3pk.w3hc.org/): passwordless Web3 authentication SDK. - [Gov](https://w3hc.github.io/gov-docs/): cross-chain, on-chain voting system. - [Rukh](https://rukh.w3hc.org/): agentic RAG service built in [Nest.js](https://nestjs.com/). - Implemented the game of Go in Solidity (a rigor exercise in contract logic). ### Developer Relations Engineer — [Arthera](https://arthera.net/) (July – December 2023) - Improved the core product through **load testing** and **upgrades to upgradeable system contracts** — work directly transferable to the robustness and security requirements of a tokenization infrastructure. - Wrote technical documentation, guides, and app examples; provided technical support online and at hackathons. - Supported partners integrating the product; organized a 150+ attendee event during [EthCC](https://ethcc.io/) 2023 in Paris. ### Developer Relations Engineer — Aurora Labs (September – December 2022) - Wrote technical documentation, guides, and app examples; provided developer support online and at hackathons on the [Aurora](https://aurora.dev/) stack. ### CEO & CTO — Āto (2020 – 2022) - Designed the product together with an IP-specialized lawyer; managed a team of six developers in a fully remote environment. - Built an NFT marketplace and live NFT auction service, in Solidity and React. ### Head of Communications — [iExec](https://iex.ec/) (2016 – 2019) - Led the ICO, raising 10,000 BTC in under 3 hours. - Organized events (200+ attendees) during [Devcon](https://devcon.org/) in Prague. ### Other experience - Customer Support Manager — [OpenClassrooms](https://openclassrooms.com/) (2014 – 2016): built the customer service function from scratch, handling 1,000+ requests weekly. - Chinese teacher — French National Education (2008 – 2013). ## Education - Degree in Chinese Studies (Philosophy, Literature and Arts) — [INALCO](https://www.inalco.fr/) (National Institute for Oriental Languages and Civilizations), Paris, 2007. ## Languages - **English**: fluent, daily working language. - **French**: native. - **Chinese**: fluent (former Chinese teacher, Chinese Studies degree from INALCO). ## Contact - [julien@strat.cc](mailto:julien@strat.cc) - +33 6 30 90 54 48 - Montpellier, France - [Website](https://julienberanger.com/) - [GitHub](https://github.com/julienbrg) - [LinkedIn](https://www.linkedin.com/in/julienberanger/)