CV
Julien Béranger
+ Claude Opus 5
Smart Contract & Full-Stack Engineer — AI / LLM integrations
Montpellier, France · julien@strat.cc · +33 6 30 90 54 48 julienberanger.com · GitHub · LinkedIn · X · Farcaster · Telegram · Element
Senior full-stack developer with 6+ years in production — TypeScript, React/Next.js, Node.js, REST APIs, CI/CD, and LLM integrations. I build complex business interfaces, data pipelines, and AI features — and I teach people how to do the same. Working languages: English, French, Chinese.
Core Skills
Languages & Frameworks
Solidity, Node.js, TypeScript, React, Next.js, Nest.js
AI & LLM
Agentic RAG systems, multi-model orchestration (Claude, ChatGPT, Mistral), LLM fine-tuning, Anthropic API integrations, Claude Code and LLM dev tooling (Zhankai), prompt and context engineering for production business workflows
Web3
Hardhat, Foundry, Ethers, Viem, Wagmi, Reown, OpenZeppelin
Zero-Knowledge
Privacy-preserving Web3 design, proof verification workflows, Rate-Limit Nullifiers (ZK API)
Developer Relations & Training
Technical docs, app examples, tutorials, live coding, workshops, hackathon mentoring, cohort facilitation in English
Engineering Practices
Git, CI/CD, Jest, DevOps, Docker
Career Summary
CEO & Lead Developer — Strat
2020 – Present · Montpellier, France
- Built an AI quoting assistant for Batappli (Systemlog, 5k+ MAU): tradespeople describe a job in a few words and get a ready-to-send quote in seconds. Shipping to production.
- Built a report-drafting tool for a partner running nursing-home compliance inspections — turning hours of manual writing into a guided, structured workflow.
- Delivered a custom RAG system for Systemlog.
- Built an NFT registry for AFNIC, the institution managing 4 million
.frdomains. - Developed multiple Web3 projects for Kleros and Hexarchia.
- Organised Web3 hackathons for UNESCO and Université Paris 8.
- Trained students at Epitech Digital School, STUDI, and emlyon business school.
- Won 1st Prize at the DAO Global Hackathon 2022 (Core DAO tech track).
Co-founder & Lead Developer — W3HC (Web3 Hackers Collective)
Feb 2023 – Present
- Designed and built Rukh, a Nest.js agentic RAG API with per-session model selection (Claude, ChatGPT, Mistral) and persistent context — live API, demo video.
- Built Zhankai, a CLI that turns any repo into structured markdown for LLM processing — 300+ downloads/month on npm, demo.
- Created w3pk, a passwordless Web3 authentication SDK with encrypted self-custodial wallets — site, docs, npm.
- Implemented ZK API, anonymous API access to LLMs using zero-knowledge proofs (TypeScript implementation of the Crapis–Buterin proposal).
- Developed Gov, an on-chain voting system for everyday people — cross-chain contracts, docs, deployer app.
- Implemented the game of Go in Solidity — live demo.
Developer Relations Engineer — Arthera
Jul 2023 – Dec 2023
- Wrote the technical documentation, guides, tutorials, and app examples.
- Led technical support online and during hackathons.
- Supported partners in integrating the product.
- Organised a 150+ attendee event during EthCC 2023 in Paris.
- Improved the core product: load testing, upgradeable system contracts.
Developer Relations Engineer — Aurora Labs
Sep 2022 – Dec 2022
- Wrote the technical documentation, guides, tutorials, and app examples.
- Led technical support online and during hackathons.
CEO & CTO — Āto
2020 – 2022
- Designed an IP-licensing product for NFTs in collaboration with an intellectual property lawyer — demo video, GitHub org.
- Contributed to EIP-5560: Redeemable NFTs.
- Managed a remote team of six developers.
- Built NFTs, an NFT marketplace template, and a live auction service in Solidity and React. Worked with authors, auction houses, and fine art galleries.
Head of Communications — iExec
2016 – 2019
- Led the ICO, raising 10,000 BTC in under 3 hours.
- Grew the Twitter account from 0 to 30k followers in a few months.
- Organised 200+ attendee events during Devcon Prague.
Customer Support Manager — OpenClassrooms
2014 – 2016
- Built the customer service function from the ground up, handling over 1,000 requests weekly.
Chinese Teacher — French National Education
2008 – 2013
- Taught students from CEFR level A1 to B2.
Teaching & Enablement
- Cohort training: Epitech Digital School, STUDI, emlyon business school — technical and non-technical audiences.
- Workshops & hackathons: organised and mentored events for UNESCO, Université Paris 8, and EthCC 2023 (150+ attendees).
- Developer relations: documentation, tutorials, app examples, live coding, and online support at Arthera and Aurora Labs.
- Classroom experience: five years teaching Chinese in the French national education system.
- Delivery languages: English (bilingual), French (native), Chinese.
Selected Projects
Rukh — agentic RAG API
Modular AI framework with a RAG system supporting multiple LLMs and personalised contexts. Pick your model per session, keep context across sessions. Live API · Assistant demo
Zhankai — LLM dev tooling
CLI that converts a repository into a structured markdown file for LLM processing. npm · Demo video
w3pk — passwordless Web3 auth SDK
WebAuthn-based self-custodial wallets, no seed phrases, with stealth addresses and ZK primitives. Site · Docs · npm · Next.js starter
ZK API — anonymous LLM access
Prepaid, ZK-proof-backed anonymous access to AI models using Rate-Limit Nullifiers.
Affix — on-chain document authentication
Anchor document hashes on-chain so anyone can verify a document is genuine and unaltered, without changing existing workflows. UI · Contracts · Demo video
Gov — on-chain governance
Voting and proposal tooling for real groups, not just DAOs. Cross-chain · Docs · Deployer
Shebam — regulated on-chain Euro payments
Payments settled in EURe via Safe — faster and cheaper than card rails, fully auditable. GitHub
Avventura — AI-driven Web3 RPG
Text-based RPG where choices, assets, and progress live on-chain, with LLM-powered storytelling. GitHub
Wulong — confidential API
Nest.js API running inside a TEE with ML-KEM-1024 encryption and SIWE authentication.
Awards & Recognition
- Optimism RetroPGF Round 3 — funding recipient for Gov, recognising its contribution to public goods.
- DAO Global Hackathon — 1st Prize (Core DAO tech track).
- GitHub — 171 repositories, Arctic Code Vault Contributor.
Education
- Degree in Chinese Studies (Philosophy, Literature and Arts) — INALCO, National Institute for Oriental Languages and Civilizations, Paris, 2007.
Languages
English (bilingual) · French (native) · Chinese