Humayou A.

Solidity developer and full-stack Web3 engineer with 6+ years building production dApps on Ethereum, Polygon, BNB Chain, Arbitrum, and Hedera. 50+ projects delivered. 100% JSS. Top Rated on Upwork. 𝐏𝐫𝐨𝐣𝐞𝐜𝐭𝐬 𝐈'𝐯𝐞 𝐬𝐡𝐢𝐩𝐩𝐞𝐝: 𝐒𝐩𝐡𝐞𝐫𝐚 𝐍𝐅𝐓 𝐌𝐚𝐫𝐤𝐞𝐭𝐩𝐥𝐚𝐜𝐞 : full-stack NFT marketplace on Hedera; Next.js frontend, Node.js backend with Redis caching and PostgreSQL, smart contract development, testing, integration and mainnet deployment 𝐃𝐞𝐜𝐞𝐧𝐭𝐫𝐚𝐥𝐢𝐳𝐞𝐝 𝐯𝐨𝐭𝐢𝐧𝐠 𝐬𝐲𝐬𝐭𝐞𝐦 𝐰𝐢𝐭𝐡 𝐛𝐢𝐨𝐦𝐞𝐭𝐫𝐢𝐜 𝐟𝐢𝐧𝐠𝐞𝐫𝐩𝐫𝐢𝐧𝐭 𝐚𝐮𝐭𝐡𝐞𝐧𝐭𝐢𝐜𝐚𝐭𝐢𝐨𝐧 (𝐖𝐞𝐛𝐀𝐮𝐭𝐡𝐧) : voters verify identity off-chain, votes recorded immutably on Ethereum via Solidity smart contract 𝐃𝐞𝐜𝐞𝐧𝐭𝐫𝐚𝐥𝐢𝐳𝐞𝐝 𝐠𝐢𝐯𝐞𝐚𝐰𝐚𝐲 𝐩𝐥𝐚𝐭𝐟𝐨𝐫𝐦 𝐰𝐢𝐭𝐡 𝐂𝐡𝐚𝐢𝐧𝐥𝐢𝐧𝐤 𝐕𝐑𝐅 : provably fair, on-chain randomness for tamper-proof winner selection, no manual intervention 𝐃𝐞𝐜𝐞𝐧𝐭𝐫𝐚𝐥𝐢𝐳𝐞𝐝 𝐜𝐞𝐫𝐭𝐢𝐟𝐢𝐜𝐚𝐭𝐞 𝐯𝐞𝐫𝐢𝐟𝐢𝐜𝐚𝐭𝐢𝐨𝐧 𝐮𝐬𝐢𝐧𝐠 𝐙𝐞𝐫𝐨-𝐊𝐧𝐨𝐰𝐥𝐞𝐝𝐠𝐞 𝐏𝐫𝐨𝐨𝐟𝐬 : validates authenticity without exposing private data, ZK proof verified by smart contract on-chain 𝐍𝐅𝐓 𝐦𝐢𝐧𝐭𝐢𝐧𝐠 𝐩𝐥𝐚𝐭𝐟𝐨𝐫𝐦𝐬 with IPFS metadata, whitelist presale, ERC-721/1155 contracts, and OpenSea integration , deployed to Ethereum mainnet 𝐃𝐞𝐅𝐢 𝐬𝐭𝐚𝐤𝐢𝐧𝐠 𝐚𝐧𝐝 𝐲𝐢𝐞𝐥𝐝 𝐟𝐚𝐫𝐦𝐢𝐧𝐠 𝐜𝐨𝐧𝐭𝐫𝐚𝐜𝐭𝐬 with gas-optimized Solidity and OpenZeppelin security standards 𝐓𝐨𝐤𝐞𝐧 𝐥𝐚𝐮𝐧𝐜𝐡𝐞𝐬 with ERC-20 presale contracts, vesting schedules, airdrop mechanics , Etherscan verified 𝐒𝐮𝐥𝐢𝐨 𝐀𝐫𝐭 : rescued and completed after multiple failed outsourcing attempts, delivered on deadline, 5-star client review Every contract is written test-first using Hardhat, deployed to testnet before mainnet, and verified on-chain before handoff. I send daily progress updates and document every architecture decision so you always know where the project stands. No surprises, no scope creep. 𝐒𝐦𝐚𝐫𝐭 𝐜𝐨𝐧𝐭𝐫𝐚𝐜𝐭 𝐬𝐭𝐚𝐜𝐤 : Solidity · ERC-20, ERC-721, ERC-1155 · Chainlink VRF · Zero-Knowledge Proofs · WebAuthn · Hardhat · Remix IDE · OpenZeppelin · IPFS · Hedera HTS 𝐂𝐡𝐚𝐢𝐧𝐬 : Ethereum · Polygon · BNB Chain · Arbitrum · Avalanche · Hedera Hashgraph 𝐖𝐞𝐛𝟑 𝐟𝐫𝐨𝐧𝐭𝐞𝐧𝐝: Ethers.js · Web3.js · MetaMask · WalletConnect · RainbowKit · Wagmi 𝐅𝐮𝐥𝐥-𝐬𝐭𝐚𝐜𝐤 : React.js · Next.js · Node.js · Express.js · Redis · PostgreSQL · MongoDB · REST APIs · TypeScript 𝐈𝐟 𝐲𝐨𝐮'𝐫𝐞 𝐥𝐚𝐮𝐧𝐜𝐡𝐢𝐧𝐠 𝐚 𝐭𝐨𝐤𝐞𝐧, 𝐛𝐮𝐢𝐥𝐝𝐢𝐧𝐠 𝐚 𝐃𝐞𝐅𝐢 𝐩𝐫𝐨𝐭𝐨𝐜𝐨𝐥, 𝐨𝐫 𝐧𝐞𝐞𝐝 𝐚 𝐬𝐦𝐚𝐫𝐭 𝐜𝐨𝐧𝐭𝐫𝐚𝐜𝐭 + 𝐟𝐫𝐨𝐧𝐭𝐞𝐧𝐝 𝐝𝐞𝐥𝐢𝐯𝐞𝐫𝐞𝐝 𝐚𝐬 𝐨𝐧𝐞 𝐜𝐨𝐦𝐩𝐥𝐞𝐭𝐞 𝐩𝐚𝐜𝐤𝐚𝐠𝐞 , 𝐬𝐞𝐧𝐝 𝐦𝐞 𝐭𝐡𝐞 𝐛𝐫𝐢𝐞𝐟 𝐚𝐧𝐝 𝐈'𝐥𝐥 𝐭𝐞𝐥𝐥 𝐲𝐨𝐮 𝐞𝐱𝐚𝐜𝐭𝐥𝐲 𝐡𝐨𝐰 𝐈'𝐝 𝐚𝐩𝐩𝐫𝐨𝐚𝐜𝐡 𝐢𝐭 𝐰𝐢𝐭𝐡𝐢𝐧 𝟒 𝐡𝐨𝐮𝐫𝐬.