Joao Renato Maximiano Menezes

JOAO RENATO MAXIMIANO MENEZES Senior Full Stack Developer | Solidity | Web3.js | React | Node.js - -https://joaorenato-portfolio.netlify.app/ https://www.linkedin.com/in/joao-renato-1314b0360/ Lauro de Freitas, Bahia, Brazil Summary Built full-stack Web3 games and blockchain-integrated applications using Solidity, React.js, and ethers.js, powering real-time NFT minting, staking, and multichain gameplay. Delivered secure, gas-efficient smart contracts (ERC-20, ERC-721, staking) deployed across Ethereum, Polygon, and BNB, connected via custom UI logic. Designed and tested wallet flows with MetaMask, WalletConnect, and dynamic on-chain/off-chain state sync. Collaborated across backend and UI teams to align game logic with token economics and smart contract utility. Focused on blockchain security, multichain compatibility, and modular frontend systems for seamless player interaction in decentralized game worlds. Experience BetterWorld Technology Virginia, United States Full Stack Developer 03/2022 - Present Web3 Engineer building cross-chain smart contract integrations and immersive gameplay logic for digital publishing and NFT rewards. • • • • • • • Developed Solidity contracts for token staking and NFT minting aligned with user engagement and reward models in virtual content spaces. Integrated MetaMask and WalletConnect into React.js interfaces using ethers.js, enabling secure wallet login and session persistence. Built multichain support flows across Ethereum, BNB, and Polygon, using provider switching and contract abstraction for dynamic execution. Designed backend services with Node.js and Firebase, supporting real-time updates and IPFS-based metadata storage for NFTs. Collaborated with UI/UX team to embed token interactions into immersive frontend logic with React.js and Tailwind CSS. Authored and executed full contract test suites with Truffle and Hardhat, enforcing upgrade-safe deployment and reentrancy protection. Guided architectural decisions for token lifecycle, reward logic, and cross-chain event syncing using Web3 best practices and gas optimizations. NuWare New Jersey, United States Software Engineer (Full Stack: .NET + React) 08/2019 - 02/2022 Full Stack Developer supporting decentralized content platforms with NFT integrations and blockchain-based identity models. • • • • • Built NFT reward mechanisms using ERC-721 contracts, tied to publishing interactions and decentralized ID verification. Used ethers.js and React to manage wallet connections, token balances, and mint confirmations across game-themed web UIs. Implemented staking logic for ERC-20 tokens within content-access protocols using lightweight, gas-optimized smart contracts. Connected user state between blockchain and Firebase with serverless functions and secure user token mapping. Developed multichain compatibility by deploying contracts to testnets on Polygon and BNB and resolving provider injection bugs. Upwork (Freelance) San Francisco, United States Freelance Developer 06/2017 - 07/2019 Blockchain game developer creating smart contracts, multichain wallet flows, and frontend experiences for NFT-based projects. • • • Delivered full NFT minting systems using Solidity, including reveal metadata, rarity configuration, and batch mint functions Integrated Web3 wallet login and token logic into client React.js dashboards for custom metaverse ecosystems. Implemented dynamic reward and staking mechanisms, with on-chain/off-chain state sync and integrated Firebase cloud functions. Key Achievements Cross-Chain NFT Staking Engine on Ethereum, Polygon, and BNB Secured and Audited Smart Contracts for Game Economy Mentored Web3 Teams on Full-Stack Blockchain Development Designed and deployed a smart contract system that allowed NFT staking with timebased rewards and multichain access. Connected contracts across Ethereum, BNB, and Polygon using abstraction patterns and wallet-provider switching logic. Cut integration time by 50% and enabled players to bridge assets between chains with secure coordination. Led security review and refactoring of staking and token contracts to prevent overflow, reentrancy, and permission misuse. Applied access control via OpenZeppelin and built tests using Hardhat to simulate attack surfaces. Achieved zero audit findings and deployed on time with full feature compliance. Provided mentorship on Solidity best practices, contract structure, and frontend-tochain interaction via ethers.js and React. Helped devs set up complete dApp environments including Hardhat, IPFS, and frontend contract interaction scaffolding. Raised code quality and enabled teams to ship faster and with fewer integration bugs. Education University of Adelaide Bachelor's Degree in Computer Software Engineering Adelaide, South Australia 02/2017 - 06/2019 Skills Skills: Solidity, Ethereum, Polygon, BNB, Web3.js, ethers.js, Hardhat, React.js, Node.js, Tailwind CSS, IPFS, Firebase, MetaMask, WalletConnect, ERC-20, ERC721, ERC-1155, Truffle, OpenZeppelin, Smart Contract Security, NFT