Freelancer profile translated to English.
Back to original languageAbout Guillaume
Looking for a Blockchain / Smart Contract Developer?
You need someone who can handle both on-chain and off-chain development?
You've come to the right place.
I am a blockchain developer specializing in Solidity and Rust (Solana).
I have over 15 years of backend experience and advanced expertise in Golang.
This dual skill set allows me to design complete Web3 architectures:
- secure smart contracts
- APIs, on-chain indexing,
- distributed services and dApps.
I can assist you with:
- Solidity Smart Contracts (EVM)
- Rust Smart Contracts (Solana, Anchor)
- Go Backend Development (APIs, indexers, microservices)
- Web3 Architecture (on-chain + off-chain)
- DeFi Protocols (AAVE, Chainlink…)
- Token creation, NFTs, marketplaces, automations
- Web3 CI/CD, documentation, code review
- Testnet/Mainnet deployment, Foundry / Hardhat
- Security, gas optimization, best practices
Projects completed:
- Solana Smart Contract for a decentralized escrow system (DEPO)
- Decentralized algorithmic stablecoin (Solidity + Foundry)
- NFT Marketplace (Allfeat Hackathon – 3rd place)
- AAVE Integration: deposit, borrow, repay
- Automated decentralized lottery (Chainlink VRF + Automation)
- Go API + Tezos delegation indexing (Go + MongoDB)
- DeFi dApp: React frontend + Solidity contracts (HelloDefi)
- Security challenges (Damn Vulnerable DeFi, Code4rena)
Autonomous, rigorous, and results-oriented, I design reliable, high-performance, and scalable Web3 solutions.
Do you have a blockchain or Web3 project?
Contact me, I respond in under an hour.
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Web 3, solidity blockchain, solidity audit, smart contracts, smart contract audit, smart contract solidity, blockchain developer, blockchain developer, rust, solana, DeFi
French
Native or bilingual
English
Fluent
Can work on-site
Paris (up to 50km), Lyon (up to 50km), Bordeaux (up to 50km), Nantes (up to 50km), Nice (up to 50km)
Experience
- DEPO - Escrow as a serviceBlockchain / Web3 Developer Solana RustMarch 2025 - May 2025 (2 months)DEPO - Escrow as a service is a Solana project developed as part of the Alyra training.The project aims to demonstrate the feasibility of a decentralized escrow on the Solana blockchain. It is a proof of concept designed to secure transactions between two parties via a smart contract, with simple fund release conditions.In a team of 3 developers, I was responsible for the Smart Contract development in Rust.My responsibilities:- Contribution to project architecture brainstorming- Development of Rust Smart Contracts with the Anchor framework on the Solana blockchain- Testnet deployment- Repository setup, CI (Github Actions)- Code review, best practicesTechnical context: Rust, Smart Contract, Solana, Anchor, Blockchain, Github, Github Action, Code review---Web 3, blockchain, smart contracts, smart contract audit, smart contract rust, blockchain developer, blockchain developer, DeFi
- Web3 side projectsBlockchain Developer / Web3 | Golang | Go | Solidity | Smart ContractDecember 2022 - April 2024 (1 year and 4 months)During this period, I worked on various projects:- Allfeat Hackathon3rd placeMusic Mint is an NFT marketplace where artists can sell their albums and tracks. (Solidity, Hardhat)- Creation of a cron job to retrieve Tezos delegations, as well as a REST API to expose this data (Golang / Go, MongoDB).https://github.com/guillaumedebavelaere/tezos-delegation- Creation of a decentralized stablecoin (pegged, algorithmic, exogenous) using Solidity and Foundry:https://github.com/guillaumedebavelaere/foundry-decentralized-stablecoin- Worked on CTF challenges. Damn Vulnerable DeFi:https://github.com/guillaumedebavelaere/damn-vulnerable-defiI also studied Code4rena contests to improve my knowledge of web3 security best practices and gas optimizations.- Creation of a script to retrieve historical data for the Surge SGR20 token using Typescript and GraphQL.- Creation of a decentralized and automated lottery application using Chainlink Automation and Chainlink VRF, Hardhat, Solidity, Typescript, Next.js, react-moralis, TailwindCSS, web3uikit, Fleek, IPFS.https://github.com/guillaumedebavelaere/hardhat-smartcontract-lotteryhttps://github.com/guillaumedebavelaere/nextjs-smartcontract-lottery- Creation of a Hardhat template repository to start a project with a pre-configured setup.https://github.com/guillaumedebavelaere/hardhat-template- Creation of a small project interacting with the AAVE protocol: depositing, borrowing, and repaying loans with Hardhat, Solidity, and ethers.js.https://github.com/guillaumedebavelaere/hardhat-defiTechnical environment: Golang, Go, Solidity, Foundry, Hardhat, Ethers, Truffle, Ganache, Typescript, React.js, GitHub Actions, Chainlink, OpenZeppelin, IPFS, Fleek, GraphQL.
- HelloDeFiWeb3 Developer | Solidity | Smart Contract | BlockchainNovember 2022 - January 2023 (2 months)HelloDefi is a decentralized application (dapp) that allows secure and transparent fund investment through the blockchain.The goal is to facilitate investment in DeFi protocols for wealth management clients.This project was developed as the final project of the blockchain developer training I completed at Alyra, the renowned French blockchain school, where I finished in the top 3 out of over 60 learners.I developed this project in a pair with a junior developer whom I mentored through pair programming. For the prototype, we interacted with AAVE's smart contracts on the Goerli testnet.We used the following technologies: web3js, truffle, react, solidity, openzeppelin (minimal proxy ERC1167 - clone factory pattern).This prototype was developed in less than two weeks.I then reworked the project on my own to use hardhat + ethers as well as other tools (solidity-coverage, solhint, hardhat-deploy plugin, waffle for using mocks, etherscan contract verification) to improve the project and be able to deploy easily on multiple blockchains.GitHub Repository: https://github.com/guillaumedebavelaere/hello-defi-hardhatTechnical environment: Solidity, Web3, Blockchain, Hardhat, Ethers, Truffle, React.js, web3js,Typescript, Github Actions, Chainlink, Openzeppelin, Vercel---Web 3, solidity blockchain, solidity audit, smart contracts, smart contract audit, smart contract solidity, blockchain developer, blockchain developer, DeFi
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Education
- Solana Rust Blockchain DeveloperAlyra Blockchain School2025Programme: - Développer des smart contracts sur Solana avec Rust - Tester, auditer et sécuriser ses smart contracts - Patterns complexes et interopérabilité des smart contracts - Créé un projet sur Solana - Intégrer les compétences clés pour évoluer dans l'écosystème Solana - Développer le Front d'une dApp Solana Contexte technique : Rust, Solana, Smart Contracts, Blockchain, Anchor, Next.js
- Ethereum Blockchain and Smart Contracts DeveloperAlyra Blockchain School2022Programme: - Compréhension du fonctionnement des blockchains - La blockchain Ethereum et son environnement - Développement solidity - Smart contract Solidity : bonnes pratiques et sécurité - Dapp et Truffle / Hardhat - Intégration et livraison continues - Finance décentralisée (DeFI) - NFT Contexte technique : Solidity, Smart Contracts, Ethereum, Typecript, Next.js, Hardhat, DeFi
Certifications
- Ethereum Smart Contract Blockchain DeveloperAlyra Blockchain School2022
- Solana Smart Contract Rust DeveloperAlyra Blockchain School2025
Skill set
Categories
- Other